Are you a current Michigan-based car shopper? A reporter would like to speak with you about your experience; please reach out to PR@Edmunds.com by 7/2 for details.
If it was, I would use Bill's data (a 2004 Prius owner that lives close to me), whose current tank is 63.6 MPG at 480 miles.
___Feel free to use it then. I burn almost half as much fuel over a given distance as you do and in the case of Bill’s, my last tanks came out to 105.21 mpg. Did you want to compare his 63.6 mpg over 490 miles to my 105.21 over the last 2,606? Feel free ;-)
Since when is 53.7 MPG poor?
___You mean your Prius II’s 49.3 lmpg, right? Given the Prius II is rated by the EPA for a 55.5 mpg combined, that is what is so poor given your 90 + thousand miles of hybrid driving experience. Even the lowly Corolla w/ Auto has an lmpg of ~ 45 mpg when I drive her.
And taking into account the E10 fuel (1.7 MPG) and the new tires (2 MPG), that average is actually 57.4 MPG.
___I use E10 so I guess I should have really posted my dash pic with the disclaimer that I actually received 119.9 mpg? Maybe my lmpg is actually 94.4 as well! You aren’t receiving EPA estimates in your Prius II as your 49.3 lmpg clearly shows. I am and have done so for every tank I have ever driven. Why is your hybrid not meeting EPA estimates? Is it due to the EPA or is it because of you? I guess you have lower fuel economy expectations is all. I certainly don’t
I gotta put my 2 cents in here, 1701a is being realistic having replaced the OEM tires watching the oil level and driving in harsh weather etc xcel otoh is showing what can be done, 115 MPG or better is not realistic for most of us, yes its achievable both would be better using mass transit or a pair of Rebooks
Hybrid is certainly not the one to save the natural resources. Even though Hybrids do achieve great MPG's, the costs associated with the production of the added equipment negate any savings the vehicle achieves during its useful life. So, in reality, hybrids just relocated the "emmisions" somewhere else.
___I am in awe! Someone actually does read the stuff we have been posting over the last year +. Have you had a close look at Toyota’s own emissions for the Prius II from cradle to grave so to speak?
___Fortunately, I am not speaking of emissions as that is not what this thread is about. It is about fuel economy which itself is derived from burning fossil fuels! With that, I am most certainly saving ~ ½ that precious fuel vs. driving the Corolla every day like I was. What the Aluminum structure came to in fossil fuel burned is another item of discussion but working in the nuclear industry, I have quite a bit of interesting information to post on the topic of emissions by burning fossil fuels for whatever uses one can consider vs. Nuclear.
Also, by someone doing 5 mph under the speed of traffic is causing other drivers to use more gas to pass them. So, in reality, yes you are saving money on gas for your self, but you are not generating a better net energy economy.
___That is an interesting topic of discussion as well. First off, you don’t seem to understand the ramifications of driving legally vs. driving illegal speeds. I can show you via screen pic or with the EPA’s own data that excessive speed(s) in whatever increments you want to discuss above ~ 37 mph burn more fuel then following the limits. Second, you seem to assume impeding traffic when traveling the speed limits in the far right hand lane. I don’t know what lane you travel above the speed limits yourself but if you haven’t noticed, there should be hundreds of signs in the state you live in stating “Slower traffic keep right”. If you are one of those that not only speed in the far right lanes but do not follow the posted signage, why are you the one to complain about my legal limit driving in the lane meant for it to save fuel?
___So does your Hybrid meet your fuel economy expectations or doesn’t it? If you are constantly speeding up and slowing down because you are in the far right lane exceeding the speed limits, I can only hope you will learn to be respectful of others who do abide by the laws of the states they drive in.
___Maybe you missed the point of my screenshot post? Of the 3 pics posted, one is my lmpg. Look at it again in case you didn’t see it. That isn’t a “best of” like the other two. Given the title of the thread, when someone can achieve a 114.4 and 116.5 mpg segment in just 2 days of driving said hybrid rated for just 70 mpg highway, I am definitely meeting my own expectations on a segment basis. At the same time, I have a 91.6 lmpg now and that is also far exceeding EPA estimates. Because of this, I am very happy to say that this hybrid’s fuel economy has exceeded my own expectations. Whether a hybrid is worth it or not all the while achieving this kind of fuel economy is another story and one you already know my opinion on. That 91.6 lmpg was achieved in similar inclement temperatures and weather given the nature of winter here north of Chicago. Maybe John has 10 degrees on me in the winter possibly as I have only seen a low of -3 degrees F in the Insight.
___As for John’s 49.3 lmpg, since it isn’t close to the EPA’s combined or city, are your expectations being met with whatever expectation you may or may not had for the Prius II?
___Let me put it another way. Is a MY (MY = Model Year) 2000 5-speed Honda Insight that is receiving 91.6 mpg over the life of the vehicle meeting your expectations given it is only rated for 60 mpg City/65 mpg Combined/70 Highway by the EPA? With that, is a Prius II with a lifetime of 49.3 mpg meeting your expectations given it is rated for at least 60 City/55.5 mpg Combined/51 Highway by the EPA? I most certainly do not drive my Insight entirely on the highway as I have to get to the highway and back to work somehow. John’s Prius II most certainly is not exclusively highway driven either for the same reason.
What the Aluminum structure came to in fossil fuel burned is another item of discussion but working in the nuclear industry, I have quite a bit of interesting information to post on the topic of emissions by burning fossil fuels for whatever uses one can consider vs. Nuclear.
I am not sure where you are going with the Al, but Al is a mineral, and is also 100% recyclable, while crude is not a mineral and is not recycleable at all. While nuclear energy is the most efficent at this point, it is not the most widely used. Due to people's inability to comprehend what actually happends, they FEAR the UNKNOWN. The way nuclear power stations operate in this stage of technology is ARCHAIC. We have a top of the line nuclear reactor heating up deutirium water which in turn heats up water used to drive steam turbines. In essence we have a steam engine with a nuclear reactor instead of coal as source of heat. Yes, steam engine is more efficient that internal combustion engine, but by making advances in nuclear fission we could derive energy without the wasted heat, and increased risks.
First off, you don’t seem to understand the ramifications of driving legally vs. driving illegal speeds. I can show you via screen pic or with the EPA’s own data that excessive speed(s) in whatever increments you want to discuss above ~ 37 mph burn more fuel then following the limits.
I know the ramifications of driving at illeagl speeds. The current speed limits imposed on the most roads in the US are the main reason for the slow downs and traffic problems. The 55 mph limit was imposed as a knee jerk reaction to the early 1970's oil embrago, as someone has produced data stating that driving above certain speed increases fuel inefficiency. It is true for some vehicles. But by reducing the drag coefficient one can achieve the same fuel efficiency at 80 mph. The current traffic conditions are a simple flow problem magnified by the lack of skill of 90% of drivers out there, who think that they are good and safe drivers. I am sure you remember that flow is limited by the size of the piping but you can drastically increase the flow by increasing pressure (speed in this case). I personally think that people should be retested every 3-5 years and it would be mandatory to attend driving schools such as Bondurant. Where people are taught how to truely drive, and be one with the vehicle, and not simple operators with a "point and shoot" skills.
Second, you seem to assume impeding traffic when traveling the speed limits in the far right hand lane. I don’t know what lane you travel above the speed limits yourself but if you haven’t noticed, there should be hundreds of signs in the state you live in stating “Slower traffic keep right”. If you are one of those that not only speed in the far right lanes but do not follow the posted signage, why are you the one to complain about my legal limit driving in the lane meant for it to save fuel?
I usually try to pass in the far left lane, but there are so many people who think that by going slow in the left lane they are going to get there faster than they would if traveled the same speed in the right lane. How many times I have seen people dart from the enterance ramp to the far left lane across ehe 3-4 lanes of traffic to claim their spot in "the fast lane" only to go slow.
Yes, I speed, and No, I don't have a hybrid. I have a very efficient gasoline only vehicle. But the slow pokes that dart in front of me, force me to downshift to pass them and gain my momentum, which in turn burns more gas.
If people really wanted to save the environment they would not be buying cars, but would have rode the bus, which has one engine that carries over 100 people, while achieving 30 or so MPG (Diesel bus). That translates to 300 mpg saved. Raplh Nader is the true Greenie, he has never had car, and I am not even sure if he posesses a driver's license.
That link provides details, which reveal the assumptions we've seen posted here. Testing conditions just plain do not match the real-world situations encountered.
Then make note that the EPA values themselves have been implied differently here than they actually are. Here's the text from the 2004 Prius window-sticker... "Actual Mileage will vary with options, driving conditions, driving habits and vehicle's condition. Results reported to EPA indicate that the majority of vehicles with these estimates will achieve between 51 and 69 mpg in the city and between 43 and 59 on the highway."
I've just been catching up the past day's posts and I'm really amazed.
Here we have people who have achieved fantastic fuel savings, and done so by driving around the speed limits and few here acutally want to learn exactly how they do it?
Are we that thick?
exel isn't the only one doing fantastic, remarkable things. According to other Insight drivers averages on the Hybrid'd database:
Mark Elvin averates 103.5MPG Wayne 91.4 Rick Reese 90.2 Eric 66.9
...amd more.
I'm recently getting around 56-58MPG im my HCH with my a family of 5 using tips learned from them.
I think we all could benifit in so many ways by learning to drive for efficiency.
"But I know of no laws that can be enforced that say "if the flow of traffic is in a speed-limit breaking range" drivers can be ticketed for driving below the range, if said range is illegal.
Is that how the law is worded? "
I'm not a lawyer, so I don't know how it is worded. But the concept is "impeding traffic". If can happen at any speed, though I doubt anyone would cite you for going the speed limit. However, 55 is 10 MPH below the speed limit on most LA freeways...
A very, very small percentage of drivers employ those techniques. I would also never drive with 50psi in my tires either. I go with the flow, and slow down for lights much earlier than the next guy. When I rented a Prius I actually got the EPA overall average. I think I can do better, but I am waiting for a while before I buy any hybrid.
55 is 10 MPH below the speed limit on most LA freeways...
I took a 100 mile trip up Interstate 15 and back home this afternoon. It was crazy how many little old ladies in Accord's and Camry's were blocking the left lane poking along at 75 miles per hour. The flow of traffic was never under 80 MPH and I was passed by a CHP on a motorcycle. The wife's 1990 LS400 got 25.2 mpg for the very quick trip.
Hello all; I am brand new to this forum. Just wanted to report I am very pleased with my mpg on my 2003 Honda Insight. Over 33,000 miles I have AVERAGED 86.2 mpg. On many longer trips I get 92-98. I am a pilot, and check accuracy using my GPS and saving fuel receipts. I mostly drive on hiways & freeways, not around town. I enjoy keeping the car extremely clean & detailed, display it @ saturday car shows. Generally speaking, excellent mpg can be achieved by 1) slowing down slightly and 2) putting a little extra air in the tires. Most people do not realize how much difference these 2 things can make. The Insight (5 spd) has a lean burn catalyst technology that is fantastic; it allows up to a 23 to 1 air-fuel ratio. This provides an extra 18 mpg or so during steady cruising. This is my 2nd Insight. My first was a 2002, and I sort of learned how to drive efficiently of that one. I sold it to my friend after putting 58,000 miles on it in one year, averaging 82 mpg. I had absolutely NO problems with the car, it was wonderful!! Billy......
I'd find the relatively recent re-categorization of Honda's Integrated Motor Assist as a "mild" hybrid amusing, if it wasn't so misleading. It's a full hybrid system, designed from the ground up to run on both electric and internal combustion power.
Promotional literature from competitors have been framing Honda's IMA as a "mild" hybrid, which is far from the case. Mild hybrids typically use an integrated starter-generator and idle-stop system, which shuts an engine down to conserve fuel under certain start-and-stop conditions. Mild hybrids achieve small but important fuel savings at nominal cost.
Honda's system achieves pretty amazing fuel economy and its scaleable, meaning it can be used in a vehicle like the Insight with a 1.0-liter three cylinder engine, a Civic Hybrid with a 1.3-liter four cylinder, or an Accord Hybrid with a 3.0-liter V-6...the latter offering greater performance than the standard V-6 version.
What's the difference if the Honda hybrids can't operate on electric power only? In the end, the Honda, Toyota, and Ford hybrids are all amazing vehicles that achieve the same kind of fuel economy and emissions goals. Remember, even though a Prius or Escape Hybrid can operate on battery power only at times, they can't do this for extended periods of time and they are not the same as battery electric vehicles, which by definition run at all times emitting zero localized emissions.
Promotional literature from competitors have been framing Honda's IMA as a "mild" hybrid, which is far from the case.
Again, welcome to the debate. Your very insightful take on the WHOLE hybrid business is refreshing. It is very tiring to see the nit picky "my hybrid is better than your hybrid" postings. Personally I find all the interest in higher efficiency vehicles long overdue.
Purchased a used (4822 miles when I got the keys) 2004 manual tranny HCH in early July. Tidbits fer ya to digest:
After 87 days of ownership: $130.62 spent on gas. 2979 miles driven. Average 34 miles per day. 22.8 cents per mile gas cost. Avg gas price paid with 6 fillups is $1.86. Avg MPG for my driven miles is 46.1 MPG, which is almost entirely City driving.
Trip B computer showed 34.4 as the "lifetime mpg" and I have since risen that to 37.8 with my newly learned Hybrid driving style.
Have noticed the peak performance on the realtime MPG meter when driving 37-42 MPH.
Starting the morning with only 1000 miles on the car and ending the day with 1370, I put in 9.5 gallons for a very satisfying 38.9 mpg. This was virtually all highway driving at 70mph. Oh how I love my new honda, it replaced a 1989 Accord with 227k miles.
How did you get the Honda Accord Hybrid early? I thought they weren't available until December 2004. I also thought the Hybrid was considered an EX model instead of and LX model.
Anyway it is great to you got 1.8 mpg better than the EPA highway estimate of 37.
Did you have to pay more than MSRP for your Accord Hybrid?
Actually, I have been getting terrible mileage with my Prius. I've had the car since spring '04 at which time, I was getting approximately 45 mpg. After a few months, I noticed that it was getting worse so I started to track it more carefully to note whether there was a problem with city driving, highway driving or both. Interestingly, the car is getting 47 mpg on the highway but through the past few months, the city driving continues to deteriorate such that I am now getting a VERY pathetic 21 mpg (not a typo)! You would think the dealership (Boston, MA) would do something but I won't bore anyone with the details of their inaction. If anyone has any idea what could be wrong, I would like to be able to tell the Toyota mechanics what to do!
it might take a while, but would follow the procedure in your owners manual for resolving problems with your car. it usually goes something like, talk to the service manager, talk to the dealer principle, call manufacturer customer service, etc... start writing letters. last resort call a local tv station, with your story about how your vehicle has not lived up to expectations. it seems like your vehicle has a problem.
2024 Ford F-150 STX, 2023 Ford Explorer ST, 91 Mustang GT vert
--Millie, before you bust any heads at the Toyota dealership, you need to be more specific about your driving habits in order to gain a proper diagnosis of the situation and eliminate the "human factor" as a reason for your poor mileage.
--Short 5 to 10 minute trips through the city will definitely put a damper on fuel economy. I typically get around 25 mpg in the first 5 minutes of travel. What do you typically get? Also, since Boston isn't exactly known for its balmy weather, I suspect Old Man Winter is doing his best to knock down your numbers even further. Do you idle your car in the cold morning to let it warm up? If so, you're getting zero miles per gallon. Combined with a short city commute, that adds up to miserable mpg averages. Also with the heater on, the engine won't cut off as often, so if you're sitting at a long stoplight just to get out of your neighborhood, the engine will keep running to supply heat... and we know what that means... 0 mpg. Sometimes I'll wait to turn on the heat until I get through that first long light so that my engine will kick off --only turning it on when the light finally turns green and the engine has to fire up anyway to accelerate the car. Not sure how much fuel that saves, but eh, seems like it should work.
--To sum it up, sounds like your engine is fine if you're getting 47 on the highway. Try shutting off the heat once the car is warmed up and notice if the engine kicks off within 5 or 10 seconds when the car is stopped. When coasting on a warm engine, does your green instantaneous mileage indicator max out? If so, I'd look to your driving habits as the real culprit. Maybe another Prius owner in the Boston area who has better luck with his/her mpg #'s can take yours for a test spin to see if the numbers change with the driver. Good Luck!
Thanks for the reply quasar4. I really wish the driving tips for Prius owners would solve the problem. My commute is longer than 5 minutes and the mileage doesn't increase upon warm up. I don't idle the car but I do put the heater on when it's cold (after all, we're talking Boston); I'm certain that impacts the mileage somewhat but not from the EPA of 60 down to 21. Importantly, I have noticed a dramatic decline in the mileage although my driving habits haven't changed. I'm convinced that something is wrong; now, I have to figure out what it is! Thanks again and please let me know if you think of anything!
Sorry to millie1, I don't have any advice, other than beginning to move up the dealer/manufacturer food chain. It seems like Toyota would be interested in fixing your problem, even if your dealer isn't. Toyota would probably be interesting in hearing that you are having an unpleasant experience with your dealer as well.
Back on the topic about hybrid mileage being good, bad, or ugly:
I am extremely happy with my Honda Civic Hybrid. I am getting:
very short city winter commute: 42-44 mpg
highway: 48-52 mpg
Where I live the winter temps range from 30-50 degrees, and we have winter oxygenated gas, so I'm hoping for even better numbers in the spring through fall.
--Millie, how are you calculating your mpg? Are you simply looking at the display and doing a rough estimate in your head? Or are you actually doing a long-term calculation based on how much gas is sucked out of the tank vs. miles traveled?
--Since the car has a fuel bladder bag that expands and contracts depending on the temperature, the amount of fuel you need to fill the tank will vary from fill-up to fill-up. If you just assume that the tank contains the full capacity of 11+ gallons, your mpg calculations will be grossly off (a USAToday reporter made this mistake in an article on hybrids last year). I usually can only fit in around 7+ gallons on an "empty" tank in the winter. The best way to calculate your avg. mpg is to keep track of all your fill-ups since you bought the car and just divide the number of gallons purchased into the total number of miles on your odometer.
--Plus, how are you differentiating between city and hwy economy? Unless you drive complete tanks in the city without mixing in hwy driving, your results will be skewed and will actually indicate a combined hwy/city mileage. Your combined mileage in the winter time should be somewhere between the high 30's and the mid 40's depending on your driving style and road and weather conditions. I have a short commute (10 mins) and the average on my current tank is 44 mpg ( on 185 miles). How long is your commute? Longer than 15 mins? During city driving, do you EVER see any of the green bars go over 25 mpg for any 5 min. period? If you drive the car in the city for 20 mins. or longer and you never see the green bars touch 40 mpg or above, or if the instantaneous mpg bar doesn't max out when coasting to a stop or down a hill, or if the engine doesn't shut off when the car is warmed up at a stoplight, than I have no idea what's going on with your car.
--If your car isn't performing as discussed above, then it should be fairly simple to duplicate these poor results when you pull into the Toyota repair shop. Just ask for a mechanic to go for a ride with you (or at least come on out and look at your display showing the sub-par mpg for your drive to the dealer) so you can prove your case. If you can't prove it, then they probably won't do much but shrug their shoulders and send you on your merry way.
Actually, I have been getting terrible mileage with my Prius. I've had the car since spring '04 at which time, I was getting approximately 45 mpg. After a few months, I noticed that it was getting worse so I started to track it more carefully to note whether there was a problem with city driving, highway driving or both. Interestingly, the car is getting 47 mpg on the highway but through the past few months, the city driving continues to deteriorate such that I am now getting a VERY pathetic 21 mpg (not a typo)! You would think the dealership (Boston, MA) would do something but I won't bore anyone with the details of their inaction. If anyone has any idea what could be wrong, I would like to be able to tell the Toyota mechanics what to do!
I am not familiar with Prius' oil requirements, but I would suspect that you either have engine oil that is overdue, or that whoever chnaged the oil put the wrong type in. I think Mobil1 0W-20 is the required oil.
--Would an overdue oil change/wrong oil drastically affect city mileage but not highway mileage? The problem --if any-- would appear to relate more to the hybrid electrical system not kicking in when it should.......but then again, I don't think millie has given enough information to accurately diagnose the situation and I'm no mechanic.
"A true hybrid means that a vehicle can run "Independently" on either gas or electric or both. Only the Prius..." -TERRYH2U
.
NO. A "true hybrid" has a plug so you can run it off solar or hydro or some other electric, and the Prius does NOT have that. Prius is NOT a "true hybrid".
What kind of trips and traffic are you experiencing? I have also found that I do better on highway than in the city, and short trips in the city are a mileage killer, especially in Winter.
I have kept careful records since I bought the car; with every fill-up, I recalculate the old fashioned way (miles since last fill-up divided by gas purchased) so it's bound to even out despite the fuel bladder bag issue. I also use the consumption meter on the car itself and that allows me to determine city vs. highway drives because I can begin to calculate when I know I'll be on the highway (that's how I recently determined that I got 47 mpg on a 200+ mile highway trip). I tend to do primarily city driving so that's been easy to calculate. I can easily show the bad mileage to the repair shop because it's recorded on the cumulative consumption data. They still seem to be shrugging.
Well, the first question should be: is it working like a hybrid should? In otherwords - shutting off at stops, starting out on the electric motor, does the braking seem normal (regenerative)? Does it seem to have the extra zip of the electric motor when climbing hills?
If you have the display set to show the power flow (the arrows indicating electric-gas-regen, etc) do they indicate proper functioning under various load conditions as mentioned above?
It can't be getting 21 mpg and still be operating properly (the hybrid system). My guess is you're running on the gas motor all the time and it's not switching over properly. Or your tranny is slipping. But your freeway mpg indicates that the gas engine part of the drivetrain is running normally, since the hybrid doesn't do much at hwy speeds. So it has to be something in the action of the electric motor or controller, seems to me.
I have kept careful records since I bought the car; with every fill-up, I recalculate the old fashioned way (miles since last fill-up divided by gas purchased) so it's bound to even out despite the fuel bladder bag issue. I also use the consumption meter on the car itself and that allows me to determine city vs. highway drives because I can begin to calculate when I know I'll be on the highway (that's how I recently determined that I got 47 mpg on a 200+ mile highway trip). I tend to do primarily city driving so that's been easy to calculate. I can easily show the bad mileage to the repair shop because it's recorded on the cumulative consumption data. They still seem to be shrugging.
What has the weather been like since you noticed the bad mileage? When was the last time the oil changed? How heavy is your "lead foot?" Are you getting batteries fully charged in short city driving trips? Do you have the heater or a/c on?
I agree with the assessments jrbldr and quasar4 made in that you need the gas-electric converter mechanism investigated. I've heard that 47 mpg is somewhat typical for highway mileage where the gas engine dominates. Even if the car was running exclusively on the gas engine, I would expect the gas mileage to be in the upper 20's to low 30's for the Prius weight/engine size. A mpg rating of 21 could indicate potentially another problem in that your transmission might be keeping you in a lower gear during city driving or that you are always "regeneratively braking" and losing mpg by the frictional power loss of the process.
Hold on a sec....Wash & wax? Unless you're unloading 40 lbs of snow & ice whats the point?
The main reason we buy Prius's is to get maximum MPG's but unfortunitly EPA ratings are far above the real world MPG's.(not unlike any of the other tested cars on the market. Hummers are EPA tested to give 12 MPG's CITY but if you ask any owner (and they're honest) they'll tell you they're lucky to get 8-9 MPG's (of course if you can afford a HUMMER who cares how bad it is.
Through out these web sites the general drift is a PRIUS gets about 43-48 highway and unlike EPA city, it seems to differ the most..with most of us getting a wider range of 35-46 MPG's. Why this is true is up to a lot of speculation. Some say different blending of winter gas, weather conditions, temperature fluxuations, and even altitude possibly having some effect. I personally see big differances with temps. Lastly I still think the PRIUS is an exceptional Hybrid car. Well designed and one the most fuel efficient cars on the road that doesn't sacrifice room and performance. Maybe thats why there's been such a demand for this car.
Hold on a sec....Wash & wax? Unless you're unloading 40 lbs of snow & ice whats the point?
Theoretically a waxed car has lower drag coefficient due to smoother surface. It works on boats and skiis. Niceley waxed boat or a pair of skiis will give you higher velosity. :-)
Greetings! Just put over 1,000 miles on a ’05 Prius in Franklin, TN (just south of Nashville). First, got to say how pleased I am with this car. The quality is just outstanding. Everything fits and feels great. A surprising amount of room in the back, suspension feels great, and just delighted with the performance. And the smart key system is mint.
The biggest thing I noticed is how this car has changed my driving habits. I’ve become obsessed with eeking out every last mile from the tank. I’ve been avoiding highways taking the routes that allow me to travel 45 to 55 MPH. I no longer speed from light to light, allowing the car to coast when I see a red light up ahead (much the annoyance, I sure, of drivers behind me. Funny how we are so desperate to get to that red light!) I’m also getting to the point where I know when the travel of the gas peddle will allow the car to coast and then kick on the electric motor. This seems to me to be the biggest trick to gaining maximum efficiency.
On my first 9 gallons my Prius reported 48 MPG. But that equates to 432 miles. I actually went 525 miles! So, either the Prius is reporting low, or I picked up some 90 miles sans gas :-). 9 gallons and 525 miles is over 58 MPG. Not bad, and hoping for better once the engine breaks in and the temp rises (been below freezing here).
So I’ve read a few posts where people say that the MPG rating displayed by the Prius is actually higher that it really is. In my experience, it seems to be lower. It would be great to travel 90 miles on electric only, but find that hard to imagine. But can’t argue with milage / fuel figures. Bottom line is that I’m delighted with the fuel efficiency of this car, especially having driven a V8 pickup before! I can’t say enough good things about it, and think every auto should use this technology.
quote jebster-"The biggest thing I noticed is how this car has changed my driving habits. I’ve become obsessed with eeking out every last mile from the tank. I’ve been avoiding highways taking the routes that allow me to travel 45 to 55 MPH. I no longer speed from light to light, allowing the car to coast when I see a red light up ahead (much the annoyance, I sure, of drivers behind me. Funny how we are so desperate to get to that red light!) I’m also getting to the point where I know when the travel of the gas peddle will allow the car to coast and then kick on the electric motor. This seems to me to be the biggest trick to gaining maximum efficiency."-end quote
That trick is ABSOLUTELY a good one for maximizing MPG. I own a 2004 HCH manual tranny and I use that trick EVERY day on my short, all city commute.
It is downright comical to watch how cars ZOOM ZOOM right by me when I am coasting up to a red light two blocks away only to see them right beside me at the red light !!!
What is this ridiculous urge people seem to have these days to RACE between lights? Don't they know that will not help them, and it is costing them extra gas money and wear and tear on their car?
Anyway, good luck and I hope the Prius exceeds your expectations as much as my HCH has exceeded mine.
Just last week, I was sitting at a light which turned green. I noticed the next light only ~50 feet ahead was still red, so I just coasted forward at 5 mph.
The guy behind me got impatient & passed & then stopped. He got out of his car and said, "What is your problem? You got a green light... why didn't you go???"
I replied that I was going at 5 mph. And only an idiot would waste precious gasoline money + wear-n-tear on their car, racing to 40mph, and then slamming on their brakes.
My previous post wished best to fellow Prius drivers. My bad. Best wishes to all hybrid drivers!!!
Yes, it is a hoot to catch up with speedy drivers at red lights! I'm not 100% sure, but I think that people do all that they can to pass me up. Can't stand being behind one of those slow electric cars! HA! Without the trainny and with the electric torque, I can jump right up to cruising speed (and just to stay on topic, have not noticed a decrease in MGP due to hard acceleration from stops to cruising speed). Great to leave them behind, but seems like nearly everyone is determined to get right back on my rear and tailgate the heck out of me. Might just be me being protective of the new ride :-)
--How do you know that you had burned 9 gallons of gas? With the fuel bladder bag expanding and contracting with the weather, if it takes 9 gallons to refill the tank, that doesn't necessarily mean that you burned 9 gallons since your last full tank. You may have burned 10.9 gallons from your original "full" tank, but cold temperatures during your refill could have shrunk the bag so as to require only 9 gallons to push the fuel indicator back to the "full" mark.
--While I can't comment on the exact accuracy of the MPG display since I haven't bothered to write down the displayed mileage/gallon with each fill (I only monitor my actual mpg), I believe the system is quite accurate.
I do not believe the concept of the bladder bag expanding is a valid argument for the gas mileage differentials. The volume coefficient of thermal expansion (at most) for a rubber is approximately 600 x 10-6 / K. Using the equation thermal expansion equation:
dV = B(V)(dT)
where dv is the change in volume, B is the coefficient of thermal expansion, V is the initial volume and dT is the temperature change,
dV = (600 x 10-6)(10 gal)(100 K) = 0.6 gallons
This 0.6 gallons is for a temperature difference of 100 K or 212 degrees Fahrenheit (For example, if you filled up in Nairobi, Kenya and then refilled in Nome, Alaska).
For the 2 and 3 gallons variations that are being cited on this forum, one would have to invoke the ideal gas equation, which is not valid for solids with an elastic resistance.
Hold it pardner! You left out other variables. The resistance factor. The outer tank and the metering mechanism and anything else that could effect the expansion/contraction of the notorious "Bladder". For those of us that OWN the 2nd generation Prius, we all know that there are obvious fluctuations in the gas gauge that leave us wondering, "what the hecks left in that darn tank". We also know we don't want to "push it" to the point of running dry and jeapardizing the hybrid system. I have been tempted when the warning lite starts flashing and I have gone as much as 67 miles B/4 pulling in for a fill-up. The most I managed to put in the tank that particular occasion was 9.1 gallons on a tank that has a maximum cap. of 11.9 gallons. I'm presently lined up to get the "fuel nozzle and new meter sys" in a few days. One other point that we owners can share...After a fill-up I have noticed a big variance in miles covered B/4 the first "bar" disappears off the gauge (as little as 38 miles & as much 128) This seems to be just too much of a fluctuation to me.
Comments
If it was, I would use Bill's data (a 2004 Prius owner that lives close to me), whose current tank is 63.6 MPG at 480 miles.
___Feel free to use it then. I burn almost half as much fuel over a given distance as you do and in the case of Bill’s, my last tanks came out to 105.21 mpg. Did you want to compare his 63.6 mpg over 490 miles to my 105.21 over the last 2,606? Feel free ;-)
Since when is 53.7 MPG poor?
___You mean your Prius II’s 49.3 lmpg, right? Given the Prius II is rated by the EPA for a 55.5 mpg combined, that is what is so poor given your 90 + thousand miles of hybrid driving experience. Even the lowly Corolla w/ Auto has an lmpg of ~ 45 mpg when I drive her.
And taking into account the E10 fuel (1.7 MPG) and the new tires (2 MPG), that average is actually 57.4 MPG.
___I use E10 so I guess I should have really posted my dash pic with the disclaimer that I actually received 119.9 mpg? Maybe my lmpg is actually 94.4 as well! You aren’t receiving EPA estimates in your Prius II as your 49.3 lmpg clearly shows. I am and have done so for every tank I have ever driven. Why is your hybrid not meeting EPA estimates? Is it due to the EPA or is it because of you? I guess you have lower fuel economy expectations is all. I certainly don’t
___Wayne R. Gerdes
Hybrid is certainly not the one to save the natural resources. Even though Hybrids do achieve great MPG's, the costs associated with the production of the added equipment negate any savings the vehicle achieves during its useful life. So, in reality, hybrids just relocated the "emmisions" somewhere else.
___I am in awe! Someone actually does read the stuff we have been posting over the last year +. Have you had a close look at Toyota’s own emissions for the Prius II from cradle to grave so to speak?
___Fortunately, I am not speaking of emissions as that is not what this thread is about. It is about fuel economy which itself is derived from burning fossil fuels! With that, I am most certainly saving ~ ½ that precious fuel vs. driving the Corolla every day like I was. What the Aluminum structure came to in fossil fuel burned is another item of discussion but working in the nuclear industry, I have quite a bit of interesting information to post on the topic of emissions by burning fossil fuels for whatever uses one can consider vs. Nuclear.
Also, by someone doing 5 mph under the speed of traffic is causing other drivers to use more gas to pass them. So, in reality, yes you are saving money on gas for your self, but you are not generating a better net energy economy.
___That is an interesting topic of discussion as well. First off, you don’t seem to understand the ramifications of driving legally vs. driving illegal speeds. I can show you via screen pic or with the EPA’s own data that excessive speed(s) in whatever increments you want to discuss above ~ 37 mph burn more fuel then following the limits. Second, you seem to assume impeding traffic when traveling the speed limits in the far right hand lane. I don’t know what lane you travel above the speed limits yourself but if you haven’t noticed, there should be hundreds of signs in the state you live in stating “Slower traffic keep right”. If you are one of those that not only speed in the far right lanes but do not follow the posted signage, why are you the one to complain about my legal limit driving in the lane meant for it to save fuel?
___So does your Hybrid meet your fuel economy expectations or doesn’t it? If you are constantly speeding up and slowing down because you are in the far right lane exceeding the speed limits, I can only hope you will learn to be respectful of others who do abide by the laws of the states they drive in.
___Wayne R. Gerdes
___Maybe you missed the point of my screenshot post? Of the 3 pics posted, one is my lmpg. Look at it again in case you didn’t see it. That isn’t a “best of” like the other two. Given the title of the thread, when someone can achieve a 114.4 and 116.5 mpg segment in just 2 days of driving said hybrid rated for just 70 mpg highway, I am definitely meeting my own expectations on a segment basis. At the same time, I have a 91.6 lmpg now and that is also far exceeding EPA estimates. Because of this, I am very happy to say that this hybrid’s fuel economy has exceeded my own expectations. Whether a hybrid is worth it or not all the while achieving this kind of fuel economy is another story and one you already know my opinion on. That 91.6 lmpg was achieved in similar inclement temperatures and weather given the nature of winter here north of Chicago. Maybe John has 10 degrees on me in the winter possibly as I have only seen a low of -3 degrees F in the Insight.
___As for John’s 49.3 lmpg, since it isn’t close to the EPA’s combined or city, are your expectations being met with whatever expectation you may or may not had for the Prius II?
___Let me put it another way. Is a MY (MY = Model Year) 2000 5-speed Honda Insight that is receiving 91.6 mpg over the life of the vehicle meeting your expectations given it is only rated for 60 mpg City/65 mpg Combined/70 Highway by the EPA? With that, is a Prius II with a lifetime of 49.3 mpg meeting your expectations given it is rated for at least 60 City/55.5 mpg Combined/51 Highway by the EPA? I most certainly do not drive my Insight entirely on the highway as I have to get to the highway and back to work somehow. John’s Prius II most certainly is not exclusively highway driven either for the same reason.
___Good Luck
___Wayne R. Gerdes
I am not sure where you are going with the Al, but Al is a mineral, and is also 100% recyclable, while crude is not a mineral and is not recycleable at all.
While nuclear energy is the most efficent at this point, it is not the most widely used. Due to people's inability to comprehend what actually happends, they FEAR the UNKNOWN. The way nuclear power stations operate in this stage of technology is ARCHAIC. We have a top of the line nuclear reactor heating up deutirium water which in turn heats up water used to drive steam turbines. In essence we have a steam engine with a nuclear reactor instead of coal as source of heat. Yes, steam engine is more efficient that internal combustion engine, but by making advances in nuclear fission we could derive energy without the wasted heat, and increased risks.
First off, you don’t seem to understand the ramifications of driving legally vs. driving illegal speeds. I can show you via screen pic or with the EPA’s own data that excessive speed(s) in whatever increments you want to discuss above ~ 37 mph burn more fuel then following the limits.
I know the ramifications of driving at illeagl speeds. The current speed limits imposed on the most roads in the US are the main reason for the slow downs and traffic problems. The 55 mph limit was imposed as a knee jerk reaction to the early 1970's oil embrago, as someone has produced data stating that driving above certain speed increases fuel inefficiency. It is true for some vehicles. But by reducing the drag coefficient one can achieve the same fuel efficiency at 80 mph.
The current traffic conditions are a simple flow problem magnified by the lack of skill of 90% of drivers out there, who think that they are good and safe drivers. I am sure you remember that flow is limited by the size of the piping but you can drastically increase the flow by increasing pressure (speed in this case). I personally think that people should be retested every 3-5 years and it would be mandatory to attend driving schools such as Bondurant. Where people are taught how to truely drive, and be one with the vehicle, and not simple operators with a "point and shoot" skills.
Second, you seem to assume impeding traffic when traveling the speed limits in the far right hand lane. I don’t know what lane you travel above the speed limits yourself but if you haven’t noticed, there should be hundreds of signs in the state you live in stating “Slower traffic keep right”. If you are one of those that not only speed in the far right lanes but do not follow the posted signage, why are you the one to complain about my legal limit driving in the lane meant for it to save fuel?
I usually try to pass in the far left lane, but there are so many people who think that by going slow in the left lane they are going to get there faster than they would if traveled the same speed in the right lane. How many times I have seen people dart from the enterance ramp to the far left lane across ehe 3-4 lanes of traffic to claim their spot in "the fast lane" only to go slow.
Yes, I speed, and No, I don't have a hybrid. I have a very efficient gasoline only vehicle. But the slow pokes that dart in front of me, force me to downshift to pass them and gain my momentum, which in turn burns more gas.
If people really wanted to save the environment they would not be buying cars, but would have rode the bus, which has one engine that carries over 100 people, while achieving 30 or so MPG (Diesel bus). That translates to 300 mpg saved. Raplh Nader is the true Greenie, he has never had car, and I am not even sure if he posesses a driver's license.
Bad math, 100x30=3000, this proves my point even better.
http://www.fueleconomy.gov/feg/info.shtml
That link provides details, which reveal the assumptions we've seen posted here. Testing conditions just plain do not match the real-world situations encountered.
Then make note that the EPA values themselves have been implied differently here than they actually are. Here's the text from the 2004 Prius window-sticker... "Actual Mileage will vary with options, driving conditions, driving habits and vehicle's condition. Results reported to EPA indicate that the majority of vehicles with these estimates will achieve between 51 and 69 mpg in the city and between 43 and 59 on the highway."
JOHN
You mean the Prius specifically or Hybrids in general......???????
Here we have people who have achieved fantastic fuel savings, and done so by driving around the speed limits and few here acutally want to learn exactly how they do it?
Are we that thick?
exel isn't the only one doing fantastic, remarkable things.
According to other Insight drivers averages on the Hybrid'd database:
Mark Elvin averates 103.5MPG
Wayne 91.4
Rick Reese 90.2
Eric 66.9
...amd more.
I'm recently getting around 56-58MPG im my HCH with my a family of 5 using tips learned from them.
I think we all could benifit in so many ways by learning to drive for efficiency.
Is that how the law is worded? "
I'm not a lawyer, so I don't know how it is worded. But the concept is "impeding traffic". If can happen at any speed, though I doubt anyone would cite you for going the speed limit. However, 55 is 10 MPH below the speed limit on most LA freeways...
I took a 100 mile trip up Interstate 15 and back home this afternoon. It was crazy how many little old ladies in Accord's and Camry's were blocking the left lane poking along at 75 miles per hour. The flow of traffic was never under 80 MPH and I was passed by a CHP on a motorcycle. The wife's 1990 LS400 got 25.2 mpg for the very quick trip.
The Insight (5 spd) has a lean burn catalyst technology that is fantastic; it allows up to a 23 to 1 air-fuel ratio. This provides an extra 18 mpg or so during steady cruising.
This is my 2nd Insight. My first was a 2002, and I sort of learned how to drive efficiently of that one. I sold it to my friend after putting 58,000 miles on it in one year, averaging 82 mpg. I had absolutely NO problems with the car, it was wonderful!! Billy......
Promotional literature from competitors have been framing Honda's IMA as a "mild" hybrid, which is far from the case. Mild hybrids typically use an integrated starter-generator and idle-stop system, which shuts an engine down to conserve fuel under certain start-and-stop conditions. Mild hybrids achieve small but important fuel savings at nominal cost.
Honda's system achieves pretty amazing fuel economy and its scaleable, meaning it can be used in a vehicle like the Insight with a 1.0-liter three cylinder engine, a Civic Hybrid with a 1.3-liter four cylinder, or an Accord Hybrid with a 3.0-liter V-6...the latter offering greater performance than the standard V-6 version.
What's the difference if the Honda hybrids can't operate on electric power only? In the end, the Honda, Toyota, and Ford hybrids are all amazing vehicles that achieve the same kind of fuel economy and emissions goals. Remember, even though a Prius or Escape Hybrid can operate on battery power only at times, they can't do this for extended periods of time and they are not the same as battery electric vehicles, which by definition run at all times emitting zero localized emissions.
Again, welcome to the debate. Your very insightful take on the WHOLE hybrid business is refreshing. It is very tiring to see the nit picky "my hybrid is better than your hybrid" postings. Personally I find all the interest in higher efficiency vehicles long overdue.
After 87 days of ownership: $130.62 spent on gas. 2979 miles driven. Average 34 miles per day. 22.8 cents per mile gas cost. Avg gas price paid with 6 fillups is $1.86. Avg MPG for my driven miles is 46.1 MPG, which is almost entirely City driving.
Trip B computer showed 34.4 as the "lifetime mpg" and I have since risen that to 37.8 with my newly learned Hybrid driving style.
Have noticed the peak performance on the realtime MPG meter when driving 37-42 MPH.
Anyway it is great to you got 1.8 mpg better than the EPA highway estimate of 37.
Did you have to pay more than MSRP for your Accord Hybrid?
YMMV,
MidCow
.. and by the way Hybrid or not 38.9 mpg is great mileage!
YMMV,
MidCow
--Short 5 to 10 minute trips through the city will definitely put a damper on fuel economy. I typically get around 25 mpg in the first 5 minutes of travel. What do you typically get? Also, since Boston isn't exactly known for its balmy weather, I suspect Old Man Winter is doing his best to knock down your numbers even further. Do you idle your car in the cold morning to let it warm up? If so, you're getting zero miles per gallon. Combined with a short city commute, that adds up to miserable mpg averages. Also with the heater on, the engine won't cut off as often, so if you're sitting at a long stoplight just to get out of your neighborhood, the engine will keep running to supply heat... and we know what that means... 0 mpg. Sometimes I'll wait to turn on the heat until I get through that first long light so that my engine will kick off --only turning it on when the light finally turns green and the engine has to fire up anyway to accelerate the car. Not sure how much fuel that saves, but eh, seems like it should work.
--To sum it up, sounds like your engine is fine if you're getting 47 on the highway. Try shutting off the heat once the car is warmed up and notice if the engine kicks off within 5 or 10 seconds when the car is stopped. When coasting on a warm engine, does your green instantaneous mileage indicator max out? If so, I'd look to your driving habits as the real culprit. Maybe another Prius owner in the Boston area who has better luck with his/her mpg #'s can take yours for a test spin to see if the numbers change with the driver. Good Luck!
Back on the topic about hybrid mileage being good, bad, or ugly:
I am extremely happy with my Honda Civic Hybrid. I am getting:
very short city winter commute: 42-44 mpg
highway: 48-52 mpg
Where I live the winter temps range from 30-50 degrees, and we have winter oxygenated gas, so I'm hoping for even better numbers in the spring through fall.
--Since the car has a fuel bladder bag that expands and contracts depending on the temperature, the amount of fuel you need to fill the tank will vary from fill-up to fill-up. If you just assume that the tank contains the full capacity of 11+ gallons, your mpg calculations will be grossly off (a USAToday reporter made this mistake in an article on hybrids last year). I usually can only fit in around 7+ gallons on an "empty" tank in the winter. The best way to calculate your avg. mpg is to keep track of all your fill-ups since you bought the car and just divide the number of gallons purchased into the total number of miles on your odometer.
--Plus, how are you differentiating between city and hwy economy? Unless you drive complete tanks in the city without mixing in hwy driving, your results will be skewed and will actually indicate a combined hwy/city mileage. Your combined mileage in the winter time should be somewhere between the high 30's and the mid 40's depending on your driving style and road and weather conditions. I have a short commute (10 mins) and the average on my current tank is 44 mpg ( on 185 miles). How long is your commute? Longer than 15 mins? During city driving, do you EVER see any of the green bars go over 25 mpg for any 5 min. period? If you drive the car in the city for 20 mins. or longer and you never see the green bars touch 40 mpg or above, or if the instantaneous mpg bar doesn't max out when coasting to a stop or down a hill, or if the engine doesn't shut off when the car is warmed up at a stoplight, than I have no idea what's going on with your car.
--If your car isn't performing as discussed above, then it should be fairly simple to duplicate these poor results when you pull into the Toyota repair shop. Just ask for a mechanic to go for a ride with you (or at least come on out and look at your display showing the sub-par mpg for your drive to the dealer) so you can prove your case. If you can't prove it, then they probably won't do much but shrug their shoulders and send you on your merry way.
I am not familiar with Prius' oil requirements, but I would suspect that you either have engine oil that is overdue, or that whoever chnaged the oil put the wrong type in. I think Mobil1 0W-20 is the required oil.
.
NO. A "true hybrid" has a plug so you can run it off solar or hydro or some other electric, and the Prius does NOT have that. Prius is NOT a "true hybrid".
troy
Please stay on-topic.
If you have the display set to show the power flow (the arrows indicating electric-gas-regen, etc) do they indicate proper functioning under various load conditions as mentioned above?
It can't be getting 21 mpg and still be operating properly (the hybrid system). My guess is you're running on the gas motor all the time and it's not switching over properly. Or your tranny is slipping. But your freeway mpg indicates that the gas engine part of the drivetrain is running normally, since the hybrid doesn't do much at hwy speeds. So it has to be something in the action of the electric motor or controller, seems to me.
What has the weather been like since you noticed the bad mileage? When was the last time the oil changed? How heavy is your "lead foot?" Are you getting batteries fully charged in short city driving trips? Do you have the heater or a/c on?
take the car to the dealer and show them the record of your mpg.
While it is there, have an oil and filter change. Rotate the tire and air them up.
Have a good wash job and wax if you can. I believe that you will work out the problems if you do these things. bjich
The main reason we buy Prius's is to get maximum MPG's but unfortunitly EPA ratings are far above the real world MPG's.(not unlike any of the other tested cars on the market. Hummers are EPA tested to give 12 MPG's CITY but if you ask any owner (and they're honest) they'll tell you they're lucky to get 8-9 MPG's (of course if you can afford a HUMMER who cares how bad it is.
Through out these web sites the general drift is a PRIUS gets about 43-48 highway and unlike EPA city, it seems to differ the most..with most of us getting a wider range of 35-46 MPG's. Why this is true is up to a lot of speculation. Some say different blending of winter gas, weather conditions, temperature fluxuations, and even altitude possibly having some effect. I personally see big differances with temps. Lastly I still think the PRIUS is an exceptional Hybrid car. Well designed and one the most fuel efficient cars on the road that doesn't sacrifice room and performance. Maybe thats why there's been such a demand for this car.
Culliganman (this is the car for these times)
Theoretically a waxed car has lower drag coefficient due to smoother surface. It works on boats and skiis. Niceley waxed boat or a pair of skiis will give you higher velosity. :-)
The biggest thing I noticed is how this car has changed my driving habits. I’ve become obsessed with eeking out every last mile from the tank. I’ve been avoiding highways taking the routes that allow me to travel 45 to 55 MPH. I no longer speed from light to light, allowing the car to coast when I see a red light up ahead (much the annoyance, I sure, of drivers behind me. Funny how we are so desperate to get to that red light!) I’m also getting to the point where I know when the travel of the gas peddle will allow the car to coast and then kick on the electric motor. This seems to me to be the biggest trick to gaining maximum efficiency.
On my first 9 gallons my Prius reported 48 MPG. But that equates to 432 miles. I actually went 525 miles! So, either the Prius is reporting low, or I picked up some 90 miles sans gas :-). 9 gallons and 525 miles is over 58 MPG. Not bad, and hoping for better once the engine breaks in and the temp rises (been below freezing here).
So I’ve read a few posts where people say that the MPG rating displayed by the Prius is actually higher that it really is. In my experience, it seems to be lower. It would be great to travel 90 miles on electric only, but find that hard to imagine. But can’t argue with milage / fuel figures. Bottom line is that I’m delighted with the fuel efficiency of this car, especially having driven a V8 pickup before! I can’t say enough good things about it, and think every auto should use this technology.
Best of luck to my fellow Prius owners!
That trick is ABSOLUTELY a good one for maximizing MPG. I own a 2004 HCH manual tranny and I use that trick EVERY day on my short, all city commute.
It is downright comical to watch how cars ZOOM ZOOM right by me when I am coasting up to a red light two blocks away only to see them right beside me at the red light !!!
What is this ridiculous urge people seem to have these days to RACE between lights? Don't they know that will not help them, and it is costing them extra gas money and wear and tear on their car?
Anyway, good luck and I hope the Prius exceeds your expectations as much as my HCH has exceeded mine.
The guy behind me got impatient & passed & then stopped. He got out of his car and said, "What is your problem? You got a green light... why didn't you go???"
I replied that I was going at 5 mph. And only an idiot would waste precious gasoline money + wear-n-tear on their car, racing to 40mph, and then slamming on their brakes.
He turned red, and then stomped off.
troy
Yes, it is a hoot to catch up with speedy drivers at red lights! I'm not 100% sure, but I think that people do all that they can to pass me up. Can't stand being behind one of those slow electric cars! HA! Without the trainny and with the electric torque, I can jump right up to cruising speed (and just to stay on topic, have not noticed a decrease in MGP due to hard acceleration from stops to cruising speed). Great to leave them behind, but seems like nearly everyone is determined to get right back on my rear and tailgate the heck out of me. Might just be me being protective of the new ride :-)
--While I can't comment on the exact accuracy of the MPG display since I haven't bothered to write down the displayed mileage/gallon with each fill (I only monitor my actual mpg), I believe the system is quite accurate.
dV = B(V)(dT)
where dv is the change in volume, B is the coefficient of thermal expansion, V is the initial volume and dT is the temperature change,
dV = (600 x 10-6)(10 gal)(100 K) = 0.6 gallons
This 0.6 gallons is for a temperature difference of 100 K or 212 degrees Fahrenheit (For example, if you filled up in Nairobi, Kenya and then refilled in Nome, Alaska).
For the 2 and 3 gallons variations that are being cited on this forum, one would have to invoke the ideal gas equation, which is not valid for solids with an elastic resistance.
Culliganman (perfecting a perfection -PRIUS)