I am not sure if by your statement ("I thought those 30+ mpg numbers you were talking about were off base"), you agree or disagree with what I stated a few weeks ago. I was very serious and accurate with those numbers of 37-38 mpg I attained in my test of driving about 25-30 miles in city driving. The big problem when talking about city driving is very short trips. Those 2-5 minute trips are killers for gas mileage due to the warm-up period. However, if you take nice 20-25 minute trips in the city your gas mileage will be well over 30 if you are conscientious about coasting as much as possible when approaching traffic lights or stopped traffic.
It is only for the first mile or so that the gas mileage will be around 20 mpg if the car has not been driven for an hour or so. However, once you drive for more than a mile or two in the city, the gas mileage will dramatically increase to over 30 mpg.
It's worse in the gas only version. My friend and test drove and RH this weekend and the car was not run for a number of hours before we test drove it. We went around 3 miles and averaged 21. Not bad!!!
On my first Prius (2001), it was true for me that trips longer than 15min tend to have better gas mileage. I reasoned that the engine had to get to optimum operating temperatures to get the best numbers. I noticed this because the cold-engine light signal would come on when i parked it for awhile.
Now on my 2nd Prius (2004, much more improved vehicle), the cold engine light would only come on after a long vacation where it is parked at home for 3 weeks. But other than that, it never came on for day-to-day driving (this is Florida). AND, I had not notice poor gas mileage performance on short trips like I did with the 1st Prius. I understand that the new Prius design has a thermos-like chamber where warmed coolant is pumped into, to keep the heat when the vehicle is turned off. You can hear the sound of an electric pump when you get out of the car. When you get into the car and turn it on, the warmed coolant is pumped out to the engine to warm it up, and because of that, you'd more likely to get the optimum gas mileage regardless of trip lengths.
What you folks are telling me, is that this early version of the Rx400h does not have that thermos feature.
If what you say is true, then I am a bit disappointed in Lexus by not including this thermos chamber on the 400h as well. Why would they not include this feature?
Please be careful with your description...over 35 mpg is not typical with this vehicle no matter how you drive...unless you never use the ICE, literally...I guess if your trip is entirely down hill, you can see this...??? My trips in bumper to bumper got me to about 32...but no more...and this was on I-95 between Richmond and D.C...
With the vehicle, the first minute or two the engine kicks on...you're not getting anywhere near 20 mpg...in fact, if you look at your dash meter, you're getting closer to 5 mpg...this is a consistant number, you will not see 20 mpg when the ICE is charging...only when the ICE stops charging the traction battery will you see an ability to get better mileage...this, of course, occurs in 1-2 minutes...in fact, even if you are coasting right out of your driveway, you won't see good mileage until the ICE stops charging!
With this being said, I have to assume that your city mileage is bumper to bumper, low speed city mileage...nothing over 20-25 mph...as this would more likely use the electric motor...if you were in NYC, you wouldn't do this well as sharp accelerations would be needed or you'd be pushed off the road!
We have argued this point already on several occasions, but what I reported a few weeks ago on the city driving gas mileage was NOT a figment of my imagination. 37-38 (don't remember the exact figure, but it is irrelevant) is what I got on that 25-30 mile test. This test was obviously not in New York but in a Midwest city (about 450,000 population for metro area). Also, I had no need for air conditioning back then.
I dispute your statement that bumper to bumper (constant stop and go) will give the you the best mpg. In this type of driving you will have to break & step on the accelerator too frequently to give you great gas mileage. In my experience, the best gas mileage with this vehicle is in "typical" city driving (going at speeds ranging from 25-45 mph) and where one has a chance to do quite a bit of coasting to traffic lights and occasional stopped traffic. This is typical in the city where I live.
As far as the 20mpg number I reported above for the warm up period, that is an average in my experiences for the FIRST 5 MINUTES of driving. I have seen it range between about 17 and 23. This is solely based on the computer calculation from the screen on the dash. I don't know about your 5mpg you are stating for the first minute or two. That seems way too low, but it does not make much difference. I am concentrating on the mpg for the first 5 minutes rather than the first 1-2 minutes.
I'll tell you what I will do. I will conduct another test of about a 30 mile stretch of driving in my city hopefully before the end of this work week and report it on this board. I am actually quite curious myself once again since now our 400h has more than 2,000 miles on it. I will have to suffer with some heat since I want to compare "apples with apples" and will not have the AC running. Hopefully, the moonroof being open along with a partially opened windows will provide enough "cooling" so that I will not bake. During that first test, it only had about 300-400 miles on it if I remember correctly. If anything, the gas mileage should be better this time if the break-in period has any validity to it. Personally, I doubt there is anything to this so called break-in period. I never recall any major differences in gas mileage between the first few hundred miles and several thousand with the various vehicles that I have owned over the years. But then again, I was not very conscientious about these things in the past.
I would also be interested to hear what any of you other folks out there are getting in terms of gas mileage in the city where you live.
The cold engine light is the lighted/blue symbol that looks like a thermometer that lights up when the engine and its coolant is cold. It's usually on the right hand side of the instrument panel.
I've one of the first Prius sold in the US back in '01 and when I started the car after it is parked outside (when i was in the Boston area) for several hrs in cool weather, the light would come on for a while. The consumption bar-graph would in-turn shows the lowest of the trip's mileage until 10+ min later. That light would also come on after we moved to FL, but in longer parked duration and cooler temperatures. There has been a lot of engineering improvements since the early model. Remember the first models got 5 free service appointments ?? and each time, they collected the data to feed back to Toyota engineers (for free).
From engineering point of view, your worst air emission occurs when: 1. running with cool engine 2. getting moving from a full stop (like after a red light)
So it makes sense to keep the engine warm at start-up, to achieve the better emission rating. It's just one of the things you can do for low emission.
I will find resource that mentions the "thermos" for you. I think it is in the Prius manual???
I am not a real automotive engineer but I spent 16+ yrs supplying chips to them and worked with their engineers. We sold chips called resolver-to-digital converters which is the sensor converter that tells the computer the exact angular position of the crank shaft. As a result, the computer would know the exact position of each piston in its own combustion cycle and can restart the engine "on a dime". This means that you will not emit unburned gas mixture, and you are LESS likely to know when the engine got started.
I agree with cyclone4 in that the best gas mileage occurs in smooth and continuous low speeds, not in stop-and-go mode. That's been my experience with the Prius.
I recall seeing a figure of 60-70% of the kinetic energy actually got captured by way of charging back to the battery. This means that you lose/waste energy when you brake, losing 30% or so. Your optimum driving is one that you won't lose that 30%.
The effect of seeing the consumption bar-graph is that I try to game it, and adjust my driving to get the best numbers than any body else !! Again, your actual gas mileage is a function of your driving "personality" and your environment. I take cyclone4's numbers are a challenge and honestly trying to beat them when I get the 400h.
Here's a quote from Prius' Pocket reference guide: "In instances when the engine starts, and/or on a short trip after the engine is stopped, the motor water pump may continue operating for a short time. This is not a concern, but a standard operation of the vehicle to ensure optimum performance."
"Shutdown Off Confirm: Use the remote or push a door-button (or the one on the hatch) when leaving your Prius. That will confirm that all the doors really did get shut tightly and the power for the hybrid system is off. If you don't, the 12-volt auxiliary battery may get drained completely or the alarm might not be able to protect the car.
Whirring Sound: There is a small electric-pump that pumps 3 liters of coolant into a thermal container (to keep it hot) every time you turn the hybrid system power OFF. When the power is turned back ON, the coolant is pump back into the engine. This process reduces emissions, by achieving warm-up much faster than with an engine that would normally have to heat itself up. This process also helps to reduce wear & tear on the engine. "
The above quote is from the Prius manual which you can download at: http://john1701a.com/prius/prius-userguide.htm This seems like it's not the official Toyota manual, but the same content ?
The bottomline is this: after you turn off the 400h, and if you don't hear a whirring sound, then the 400h does not have this thermos. And yes, I am disappointed. My Prius 04 has this sound every time! It is the sound of the electric coolant pump. From your comments, the 400h does not have this feature... may be the next redesign.
Correct, steady state, even for a hybrid, is more efficient. Otherwise, you would have a perpetual motion machine.
A unit of kinetic energy must go through a very long path to get from the motion of the vehicle back out to drive the vehicle again. With all of the components and processes involved (generator, power electronics, battery charge and discharge, motor), each with their own inefficiency, you are much better off leaving the energy in the form of kinetic energy of the moving vehicle. The only time you want to capture energy is when your only other choice is to hit the brakes and throw it away as heat. Hybrids just make stop and go less inefficient.
I would expect progressively better MPG as speeds decrease, though the improvements would be progressively smaller, since the power necessary to overcome drag goes by the cube of the speed. Eventually parasitic loads, including the energy necessary to keep the engine running (idle), will make slower speeds less efficient.
Stop and go traffic will ALWAYS yeild the lowest emissions and the best FUEL ECONOMY....!!
In comparison to an equivalently sized, weight, and comparable equipped vehicle.
That car just ahead, or behind, you in that stop and go traffic is simply generating HEAT during braking or coastdown. Your Hybrid generates electricity to help you get up and going next.
Driving at a reasonably constant speed, any speed, the hybrid system is actually a detriment to good fuel economy.
Sit in your RX400 for about 5 minutes and you may hear the noise....I do notice a whirling noise in the car several minutes after I shut it off...I tend to use the bluetooth in the car and am sometimes too lazy to get out (like when it's raining heavily)...there is a 'whirling noise' several minutes after shut-off in the RX....you may have to wait longer...you will hear it!
Okay Cyclone...let's see what your new test shows!!!
When I was on I-95, I was in bumper to bumper...the car NEVER needed the ICE for acceleration as traffic was slow and stopping frequently...you can't beat mileage like this when your electric motors are the only things propelling your vehicle (except when the ICE kicked in every 15-20 minutes to charge the battery)...this is where I got the best mileage...about 32 mpg...
As far as 25-45 mph ranges allowing for best mileage...you'd need to have very few lights in your path...my area has lights everywhere...you MUST get the ICE going to accelerate even on a 35 mph road or the people behind you will 'beep' you...so, if you're stopping and starting all the time on roads like this, your mileage will suffer...also, my area is very hilly...so you can coast at times, but you get nailed when you have to stop on a light going up a hill...this drinks your gas!
However, if you can coast a lot between lights, on level ground, you will do quite well...when you accelerate, you can do so softly, so as to not drive the mileage gauge into the ground...on hills this is hard to do...
As I said in earlier post, my original 22.9 mpg 'local' roads number is now up close to 25 mpg..so, it is improving...the highway is still around 27 for me...I'm fine with these numbers as I am able to use power when needed...
"As I said in earlier post, my original 22.9 mpg 'local' roads number is now up close to 25 mpg..so, it is improving...the highway is still around 27 for me...I'm fine with these numbers as I am able to use power when needed..."
I'm still shocked at these numbers, my 2003 CR-V gets 22 / 27. I realize I'm a couple of seconds longer to 60 MPH, but then it is 1/2 the cost. (and to be fair, probably 1/2 of the luxury!)
Saturday morning June 11, 10:00-11:30, the Madison Hybrid Group will meet at the Bear Rock Cafe in Middleton, Wisconsin.
We’ll have updates about upcoming hybrids and in addition to your own hybrid, there will be a hard-to-find Lexus RX 400h available for exploring.
To complement our usual hybrid car discussion we will also cover topics like: - The hybrid car rally that took place out east (Plug-in Prius 102 mpg!) - Who’s going to the July MHG Brewers Event and how are you getting there? - Local drives, parades and other events - Even if you don’t own a hybrid car, but want to find out more about hybrids, feel free to join us. Fun is guaranteed!
If you know you are coming, post a reply here, or email me at the address in my profile. (MadsionHybridGroup a t gmail dot com). That way we obtain a big enough table for our group.
See you there!
Eric Powers
P.S. We have another Hybrid Car Event in July at Miller Park in Milwaukee that I will post shortly. $10 for a ticket to the game plus you get a free hot dog and soda.
I'm still shocked at these numbers, my 2003 CR-V gets 22 / 27. I realize I'm a couple of seconds longer to 60 MPH, but then it is 1/2 the cost. (and to be fair, probably 1/2 of the luxury!)
I am sure if you drove 400h, you will get a better mileage. I believe the driver and the driving style does matter. You should try.
Why does the RH get better highway fuel economy than the RX330 if it traveling on the highway? Please explain... otherwise Toyota has invested billions for nothing.
The 400h GETS BETTER HIGHWAY MPG THAN THE 330, even though it has more power. The batteries should not do much on the highway, but there you are, certainly not a detrement. There are additional advantages to the Toyota system other than batteries, like the ECVT and smart engine computer keeping the engine at the most efficient operating conditions, coasting and regenerating downhill, detuned engine (better mpg with lower octane).
The Toyota system is really a new way to use a combustion engine to move a car, with many advantages beyond batteries. By decoupling the engine speed from the road speed, and allowing the car to capture energy (both from the brakes and engine) to use when needed, the car can be run more efficiently under any conditions. That advantage is greatest in stop and go driving, but exists always, except maybe the first few minutes after startup.
Also, a hybrid will indeed get better mpg in stop and go than a non-hybrid (that's the point), but what I and others are saying is that a hybrid at a steady speed will get better mpg than a hybrid in stop and go. Are you arguing that if two hybrids are driven side by side, on at a steady 20 mph, one at 0-40 mph averageing 20 mph, that the one slowing down and speeding up would be more efficient?
At this time there are only two Nextel bluetooth phones. The Blackberry and the i605. My brother has his Blackberry working in his LX470 so it should work in a 400h.
I have the i605 working in my RX400h. There are several steps you have to take to get it properly working and are found in the Nextel manual. When I start my 400h the navigation screen reports that I am bluetooth connected. This can be verified by pushing the phone on button located on the steering wheel.
I've heard rumors that some bluetooth phones may not work and wanted to be sure.
The BBerry is an awkward phone to carry around. The i605 is a far nicer biz phone at near $300. There's rumor that Nextel is coming out with a flip phone bluetooth similar to the i530, but I was given the December date of release.
So the i605 seems like the most viable option. Do you experience any faster drain on phone battery when using bluetooth mode in the 400h?
Agree with what you are saying save for the following point...
At steady speeds, with hilly roads, you WON"T do that great...if you're on a flat road and can coast for long periods of time, you'll do fine...I don't know what portion of us live in less populated areas...I certainly don't!...
However, the hybrid synergy does great with bumper to bumper traffic as the ICE is not used at all...period...darn thing isn't even on! (unless recharging)...this is why the 'city' rating is 31...the 31 city rating has nothing to do with coasting around on the roads at a steady speed...in fact, that's more like the 27 EPA listing for highway..difference is that at 45 as opposed to 65 mph, you will burn less gas maintaining the speed...hence the better mileage at the slightly lower speed...(I'd still keep it in cruise to maximize efficiency)...
You wrote..."Are you arguing that if two hybrids are driven side by side, on at a steady 20 mph, one at 0-40 mph averageing 20 mph, that the one slowing down and speeding up would be more efficient? "
The hybrid that is stopping and starting would not do well due to ICE having to kick in more...coasting around at 20 mph is more desirable...remember though, that the the 31 EPA mpg refers to start and stop at low speeds, using primarily the electric motors, not the ICE...getting up and over 20 mph and coasting at such in any place other than a parking lot will require use of the ICE...
... so I can get the pairing done and answer the phone no problem. I even figured out how to leave the card and take the call with me. BUT...
If I dial out using the phone then the car takes over, albeit without letting me talk or hear for the first minute or so... This drives me and my callers crazy.
"At steady speeds, with hilly roads, you WON"T do that great"
Hilly driving is a mild form of stop and go driving: fluctuating engine load. The hybrid system's strength is leveling out fluctuating load demands on the engine by removing or adding electric power. I think a hybrid will do better than a conventional car on hilly driving. As I said, I think a hybrid will do better than a conventional in any condition, except the first mile, but with the advantage decreasing in steady speed and load conditions where the batteries do no help as much.
A hybrid will get better mileage in the flats than the hills, since it is subject to the laws of physics just like any other car. A car that gets better MPG in the hills, or in stop and go, is a perpetual motion machine. Because of inefficiencies, you capture less than 100% of the available energy of a hill or stop, and you deliver less than 100% of what you actually captured when you accelerate again. You would have to capture and deliver more than 100% of the available energy to do better than the car in the flats at the same speed: perpetual motion. The reason stop and go MPG seems so good is that the average speed is very low (10mph or less), but if you drove that actual average speed steady, you would do better than the stop and go MPG.
"The hybrid that is stopping and starting would not do well due to ICE having to kick in more...coasting around at 20 mph is more desirable...remember though, that the the 31 EPA mpg refers to start and stop at low speeds"
Yes, 31 mpg for slow stop and go, but better for slow steady driving like highway traffic where you don't have to stop, or at least not quickly. This is why people are observing mid 30's under certain conditions, better than EPA city. They see this when they drive slow, but without much stopping, only coast down.
The battery on the i605 leaves much to be desired. I can usually get about a day and a half before it is drained and I am not a heavy user. I keep an automobile charger cord in my 400h and charge the battery when needed.
In order to get the best reception it is best to keep the antenna on the i605 extended. There is a nice little compartment in the 400h center console where you can stand the phone up while driving.
"Do you think that during highway driving because the 400h is only using front wheel drive the result is better mpg? "
Yes. That is one of the poor decisions that Ford made with the Escape Hybrid, they use a driveshaft from front to rear to provide mechanical 4WD. Even with a torque split device, that stuff is always turning. The electric only rear hurts 400h off road capabilities, but I hear the Hybrid Escape is no off road star either, despite shaft drive. Another advantage of electric 4WD is the ability to capture braking energy from all four wheels, and balance the front to rear brake forces. The rear brakes don't do half the work, but maybe 1/4? That makes it a more efficient hybrid.
I am curious about how many RX 400h buyers actually use their moonroofs. It would be interesting to hear from moonroof enthusiasts. Do you enjoy the light that comes through the closed moonroof or do you open it to let fresh air in? Or both? Is it quiet at high speeds? Given a choice, would you pay extra for just the moonroof?
Here in Florida, I can't remember ever seeing an open moonroof on any type of car. It is a place where water and/or heat may leak into the car. It is heavy, and worse, the weight is at the highest point in the car, reducing stabililty. It reduces headroom. It is another maintenance item.
I understand that in other parts of the US it may also be a valued feature. I would really like to know if it is something worthwhile. I am on the list to buy a Highlander hybrid and am trying to decide whether to get the option package or wait for the base car w/o moonroof. I believe 100% of Lexus hybrids have moonroofs so it should be a fair sized sample.
It is not quiet enough to listen to classical music. My wife has one in her 1990 LS400 that has not been opened 10 time in 16 years. That includes to let the light in. That $1400 option is worth about $400 in 3 years. I see the new LS430 it is standard equipment. I think it is that it looks cool. I would not have paid extra on my new Passat if it was not standard EQ. If it is near worthless in San Diego, I would say that is true in most of the USA. If it would open up far enough to stand up and shoot rabbits racing across the desert it may be worthwhile.
Even though, I only open the moonroof rather infrequently, I love the open feel to it with the glass above. I absolutely love sunlight. As the late John Denver sang on some of his songs how his beloved Rocky Mountains gave him a "high", so does sunlight give me a "high". Even on cloudy days, I like the idea of light coming from above. So for me anyway, I would not purchase a car without a moonroof.
Short term results such as this are strickly the result of having previously stored energy in the batteries. Eventually that energy must be replenished and the ONLY way to do that is via the consumption of gasoline. Even the energy recovered via regenerative braking is the result of momentum created by burning gasoline.
We currently own three autos -- 2000 Avalon, 2005 RL and 2006 400h. All have moonroofs. I would not buy a new car without one. I know my wife, however, couldn't care less whether it's there or not. She does, however, talk on the phone a lot while in the car. An open moonroof of course increases the noise in the car materially. It becomes an irritant to her to have to close the thing every time the phone rings. For me, it really enhances the driving experience, whether it's open or just with the shade portion slid open so you can see through the glass.
I've owned numerous cars with moonroofs and I can count on one hand how many times I've used them. To me, they're a waste of money. Add to that the loss of headroom. I never had any leaks but that's a concern after a few years too. I guess everyone has their needs.
I believe you are wrong here wwest. As I indicated above, I was at the dealer to show them the results yesterday for about 5-8 minutes. I never turned the ignition off. I noticed that the battery diagram was about as low as I have seen it (only 3 bars showing) after this visit to the dealer. However, shortly thereafter, when driving for about a couple miles and naturally applying the breaks at times for stop lights, etc., the battery diagram went back to normal. Doesn't this prove your theory wrong? In other words, the system re-generates itself over and over again during normal city driving and the gas mileage will not adversely affect the gas mileage in the long term. Thus, I believe, I would still be averaging about 40 mpg if I had driven in the same type of environment and the same driving habits in the city until "hell froze over".
Is that the system uses the ICE to recharge the batteries as sort of a last resort. It "wants" to rely on the regenerative capability "first" since that is literally FREE "fuel". So it waits for the batteries to go deeper into discharge before it resorts to firing up the ICE. Unless of course the ICE gets fired up for another reason, say to keep the catalyst fired off.
So, yes, the more times you brake, or coastdown the more often the battery will get recharged for "free". On the other hand if you are on I5 from Seattle to Portland, a reasonably FLAT route, with light traffic (it happens) and with cruise set there is very little opportunity for the use of regenerative effects to recharge the batteries.
Even at a constant speed the electric motor that sets the CVT ratio must always be energized. And given that "constant speed" is non-existent anytime you accelerate even slightly the second electric motor will kick in to prevent the ICE from having to "rev" up.
That's why the city MPG rating is always better than highway, highway cruise ofters very little opportunity to recover inertial energy via regenerative braking or simulation of engine compression braking.
Suppose you start out with the computer reset and with fully charged batteries and drive slowly at a constant speed until the ICE is forced to kick in due to low battery charge. Since absolutely no gasoline was consumed up to this point what does the computer indicate for MPG?
Infinity?
Unless the computer somehow keeps track of how much battery recharge was "free" vs via the ICE it cannot possibly compute the correct MPG in the short term.
Absent this bit of knowledge, battery charge source, ICE% vs regeneration%, It is impossible for any of us to compute average MPG except over several tanks of gas, maybe even 10.
Loss of headroom? I've always had the sense that I was gaining headroom. Maybe that's a false impression. I've had many Toyotas equipped with moonroofs and have not encountered a headroom problem (I'm 6') and have never had one leak As you say, "...everyone has their needs." Guess that's why they're optional..
Agreed... I had a audi allroad and it came standard with the sunroof. I did not want it, but had to take it. I always had it close except if was a nice 60 degree day. Doesn't happen too often. I guess where you are located is important. And yes... having a sunroof usually decreases headroom.
I use the moonroof the most when I'm not actually driving the car. It's great to park it with the moonroof angled up and the sun shade drawn back only about an inch, so that the hot air can escape but the sunlight doesn't come in. It makes for a much more pleasant experience getting back into the car after a tennis match at the club...
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I am not sure if by your statement ("I thought those 30+ mpg numbers you were talking about were off base"), you agree or disagree with what I stated a few weeks ago. I was very serious and accurate with those numbers of 37-38 mpg I attained in my test of driving about 25-30 miles in city driving. The big problem when talking about city driving is very short trips. Those 2-5 minute trips are killers for gas mileage due to the warm-up period. However, if you take nice 20-25 minute trips in the city your gas mileage will be well over 30 if you are conscientious about coasting as much as possible when approaching traffic lights or stopped traffic.
If you are a soccer mom and most of your trips are less than 3 miles, what should you expect for an average MPG?
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On my first Prius (2001), it was true for me that trips longer than 15min tend to have better gas mileage. I reasoned that the engine had to get to optimum operating temperatures to get the best numbers. I noticed this because the cold-engine light signal would come on when i parked it for awhile.
Now on my 2nd Prius (2004, much more improved vehicle), the cold engine light would only come on after a long vacation where it is parked at home for 3 weeks. But other than that, it never came on for day-to-day driving (this is Florida). AND, I had not notice poor gas mileage performance on short trips like I did with the 1st Prius. I understand that the new Prius design has a thermos-like chamber where warmed coolant is pumped into, to keep the heat when the vehicle is turned off. You can hear the sound of an electric pump when you get out of the car. When you get into the car and turn it on, the warmed coolant is pumped out to the engine to warm it up, and because of that, you'd more likely to get the optimum gas mileage regardless of trip lengths.
What you folks are telling me, is that this early version of the Rx400h does not have that thermos feature.
Hmm!
Please be careful with your description...over 35 mpg is not typical with this vehicle no matter how you drive...unless you never use the ICE, literally...I guess if your trip is entirely down hill, you can see this...??? My trips in bumper to bumper got me to about 32...but no more...and this was on I-95 between Richmond and D.C...
With the vehicle, the first minute or two the engine kicks on...you're not getting anywhere near 20 mpg...in fact, if you look at your dash meter, you're getting closer to 5 mpg...this is a consistant number, you will not see 20 mpg when the ICE is charging...only when the ICE stops charging the traction battery will you see an ability to get better mileage...this, of course, occurs in 1-2 minutes...in fact, even if you are coasting right out of your driveway, you won't see good mileage until the ICE stops charging!
With this being said, I have to assume that your city mileage is bumper to bumper, low speed city mileage...nothing over 20-25 mph...as this would more likely use the electric motor...if you were in NYC, you wouldn't do this well as sharp accelerations would be needed or you'd be pushed off the road!
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We have argued this point already on several occasions, but what I reported a few weeks ago on the city driving gas mileage was NOT a figment of my imagination. 37-38 (don't remember the exact figure, but it is irrelevant) is what I got on that 25-30 mile test. This test was obviously not in New York but in a Midwest city (about 450,000 population for metro area). Also, I had no need for air conditioning back then.
I dispute your statement that bumper to bumper (constant stop and go) will give the you the best mpg. In this type of driving you will have to break & step on the accelerator too frequently to give you great gas mileage. In my experience, the best gas mileage with this vehicle is in "typical" city driving (going at speeds ranging from 25-45 mph) and where one has a chance to do quite a bit of coasting to traffic lights and occasional stopped traffic. This is typical in the city where I live.
As far as the 20mpg number I reported above for the warm up period, that is an average in my experiences for the FIRST 5 MINUTES of driving. I have seen it range between about 17 and 23. This is solely based on the computer calculation from the screen on the dash. I don't know about your 5mpg you are stating for the first minute or two. That seems way too low, but it does not make much difference. I am concentrating on the mpg for the first 5 minutes rather than the first 1-2 minutes.
I'll tell you what I will do. I will conduct another test of about a 30 mile stretch of driving in my city hopefully before the end of this work week and report it on this board. I am actually quite curious myself once again since now our 400h has more than 2,000 miles on it. I will have to suffer with some heat since I want to compare "apples with apples" and will not have the AC running. Hopefully, the moonroof being open along with a partially opened windows will provide enough "cooling" so that I will not bake. During that first test, it only had about 300-400 miles on it if I remember correctly. If anything, the gas mileage should be better this time if the break-in period has any validity to it. Personally, I doubt there is anything to this so called break-in period. I never recall any major differences in gas mileage between the first few hundred miles and several thousand with the various vehicles that I have owned over the years. But then again, I was not very conscientious about these things in the past.
I would also be interested to hear what any of you other folks out there are getting in terms of gas mileage in the city where you live.
I've one of the first Prius sold in the US back in '01 and when I started the car after it is parked outside (when i was in the Boston area) for several hrs in cool weather, the light would come on for a while. The consumption bar-graph would in-turn shows the lowest of the trip's mileage until 10+ min later. That light would also come on after we moved to FL, but in longer parked duration and cooler temperatures. There has been a lot of engineering improvements since the early model. Remember the first models got 5 free service appointments ?? and each time, they collected the data to feed back to Toyota engineers (for free).
From engineering point of view, your worst air emission occurs when:
1. running with cool engine
2. getting moving from a full stop (like after a red light)
So it makes sense to keep the engine warm at start-up, to achieve the better emission rating. It's just one of the things you can do for low emission.
I will find resource that mentions the "thermos" for you. I think it is in the Prius manual???
I am not a real automotive engineer but I spent 16+ yrs supplying chips to them and worked with their engineers. We sold chips called resolver-to-digital converters which is the sensor converter that tells the computer the exact angular position of the crank shaft. As a result, the computer would know the exact position of each piston in its own combustion cycle and can restart the engine "on a dime". This means that you will not emit unburned gas mixture, and you are LESS likely to know when the engine got started.
I recall seeing a figure of 60-70% of the kinetic energy actually got captured by way of charging back to the battery. This means that you lose/waste energy when you brake, losing 30% or so. Your optimum driving is one that you won't lose that 30%.
The effect of seeing the consumption bar-graph is that I try to game it, and adjust my driving to get the best numbers than any body else !! Again, your actual gas mileage is a function of your driving "personality" and your environment. I take cyclone4's numbers are a challenge and honestly trying to beat them when I get the 400h.
"In instances when the engine starts, and/or on a short
trip after the engine is stopped, the motor water
pump may continue operating for a short time. This is
not a concern, but a standard operation of the vehicle
to ensure optimum performance."
You can download the pocket guide at:
http://prg.toyotapartsandservice.com/pdfs/2005_Prius.pdf
and look on page 3.
I recall a more elaborate explaination in the user manual which I still trying to find.
Off Confirm: Use the remote or push a door-button (or the one on the hatch) when leaving your Prius. That will confirm that all the doors really did get shut tightly and the power for the hybrid system is off. If you don't, the 12-volt auxiliary battery may get drained completely or the alarm might not be able to protect the car.
Whirring Sound: There is a small electric-pump that pumps 3 liters of coolant into a thermal container (to keep it hot) every time you turn the hybrid system power OFF. When the power is turned back ON, the coolant is pump back into the engine. This process reduces emissions, by achieving warm-up much faster than with an engine that would normally have to heat itself up. This process also helps to reduce wear & tear on the engine. "
The above quote is from the Prius manual which you can download at:
http://john1701a.com/prius/prius-userguide.htm
This seems like it's not the official Toyota manual, but the same content ?
The bottomline is this: after you turn off the 400h, and if you don't hear a whirring sound, then the 400h does not have this thermos. And yes, I am disappointed. My Prius 04 has this sound every time! It is the sound of the electric coolant pump. From your comments, the 400h does not have this feature... may be the next redesign.
A unit of kinetic energy must go through a very long path to get from the motion of the vehicle back out to drive the vehicle again. With all of the components and processes involved (generator, power electronics, battery charge and discharge, motor), each with their own inefficiency, you are much better off leaving the energy in the form of kinetic energy of the moving vehicle. The only time you want to capture energy is when your only other choice is to hit the brakes and throw it away as heat. Hybrids just make stop and go less inefficient.
I would expect progressively better MPG as speeds decrease, though the improvements would be progressively smaller, since the power necessary to overcome drag goes by the cube of the speed. Eventually parasitic loads, including the energy necessary to keep the engine running (idle), will make slower speeds less efficient.
In comparison to an equivalently sized, weight, and comparable equipped vehicle.
That car just ahead, or behind, you in that stop and go traffic is simply generating HEAT during braking or coastdown. Your Hybrid generates electricity to help you get up and going next.
Driving at a reasonably constant speed, any speed, the hybrid system is actually a detriment to good fuel economy.
Okay Cyclone...let's see what your new test shows!!!
When I was on I-95, I was in bumper to bumper...the car NEVER needed the ICE for acceleration as traffic was slow and stopping frequently...you can't beat mileage like this when your electric motors are the only things propelling your vehicle (except when the ICE kicked in every 15-20 minutes to charge the battery)...this is where I got the best mileage...about 32 mpg...
As far as 25-45 mph ranges allowing for best mileage...you'd need to have very few lights in your path...my area has lights everywhere...you MUST get the ICE going to accelerate even on a 35 mph road or the people behind you will 'beep' you...so, if you're stopping and starting all the time on roads like this, your mileage will suffer...also, my area is very hilly...so you can coast at times, but you get nailed when you have to stop on a light going up a hill...this drinks your gas!
However, if you can coast a lot between lights, on level ground, you will do quite well...when you accelerate, you can do so softly, so as to not drive the mileage gauge into the ground...on hills this is hard to do...
As I said in earlier post, my original 22.9 mpg 'local' roads number is now up close to 25 mpg..so, it is improving...the highway is still around 27 for me...I'm fine with these numbers as I am able to use power when needed...
Headless
I'm still shocked at these numbers, my 2003 CR-V gets 22 / 27. I realize I'm a couple of seconds longer to 60 MPH, but then it is 1/2 the cost. (and to be fair, probably 1/2 of the luxury!)
Saturday morning June 11, 10:00-11:30, the Madison Hybrid Group will meet at the Bear Rock Cafe in Middleton, Wisconsin.
We’ll have updates about upcoming hybrids and in addition to your own hybrid, there will be a hard-to-find Lexus RX 400h available for exploring.
To complement our usual hybrid car discussion we will also cover topics like:
- The hybrid car rally that took place out east (Plug-in Prius 102 mpg!)
- Who’s going to the July MHG Brewers Event and how are you getting there?
- Local drives, parades and other events
-
Even if you don’t own a hybrid car, but want to find out more about hybrids, feel free to join us. Fun is guaranteed!
If you know you are coming, post a reply here, or email me at the address in my profile. (MadsionHybridGroup a t gmail dot com). That way we obtain a big enough table for our group.
See you there!
Eric Powers
P.S. We have another Hybrid Car Event in July at Miller Park in Milwaukee that I will post shortly. $10 for a ticket to the game plus you get a free hot dog and soda.
I am sure if you drove 400h, you will get a better mileage. I believe the driver and the driving style does matter. You should try.
Hong.
The Toyota system is really a new way to use a combustion engine to move a car, with many advantages beyond batteries. By decoupling the engine speed from the road speed, and allowing the car to capture energy (both from the brakes and engine) to use when needed, the car can be run more efficiently under any conditions. That advantage is greatest in stop and go driving, but exists always, except maybe the first few minutes after startup.
Also, a hybrid will indeed get better mpg in stop and go than a non-hybrid (that's the point), but what I and others are saying is that a hybrid at a steady speed will get better mpg than a hybrid in stop and go. Are you arguing that if two hybrids are driven side by side, on at a steady 20 mph, one at 0-40 mph averageing 20 mph, that the one slowing down and speeding up would be more efficient?
Don't have the 40 large ones to spare...
Does it work? and which model(s)?
Thanks.
My brother has his Blackberry working in his LX470 so it should work in a 400h.
I have the i605 working in my RX400h. There are several steps you have to take to get it properly working and are found in the Nextel manual. When I start my 400h the navigation screen reports that I am bluetooth connected. This can be verified by pushing the phone on button located on the steering wheel.
I've heard rumors that some bluetooth phones may not work and wanted to be sure.
The BBerry is an awkward phone to carry around. The i605 is a far nicer biz phone at near $300. There's rumor that Nextel is coming out with a flip phone bluetooth similar to the i530, but I was given the December date of release.
So the i605 seems like the most viable option. Do you experience any faster drain on phone battery when using bluetooth mode in the 400h?
At steady speeds, with hilly roads, you WON"T do that great...if you're on a flat road and can coast for long periods of time, you'll do fine...I don't know what portion of us live in less populated areas...I certainly don't!...
However, the hybrid synergy does great with bumper to bumper traffic as the ICE is not used at all...period...darn thing isn't even on! (unless recharging)...this is why the 'city' rating is 31...the 31 city rating has nothing to do with coasting around on the roads at a steady speed...in fact, that's more like the 27 EPA listing for highway..difference is that at 45 as opposed to 65 mph, you will burn less gas maintaining the speed...hence the better mileage at the slightly lower speed...(I'd still keep it in cruise to maximize efficiency)...
You wrote..."Are you arguing that if two hybrids are driven side by side, on at a steady 20 mph, one at 0-40 mph averageing 20 mph, that the one slowing down and speeding up would be more efficient? "
The hybrid that is stopping and starting would not do well due to ICE having to kick in more...coasting around at 20 mph is more desirable...remember though, that the the 31 EPA mpg refers to start and stop at low speeds, using primarily the electric motors, not the ICE...getting up and over 20 mph and coasting at such in any place other than a parking lot will require use of the ICE...
Headless
If I dial out using the phone then the car takes over, albeit without letting me talk or hear for the first minute or so... This drives me and my callers crazy.
Any ideas?
In what way(s) are the RX 330 and RX 400h back views different?
Hilly driving is a mild form of stop and go driving: fluctuating engine load. The hybrid system's strength is leveling out fluctuating load demands on the engine by removing or adding electric power. I think a hybrid will do better than a conventional car on hilly driving. As I said, I think a hybrid will do better than a conventional in any condition, except the first mile, but with the advantage decreasing in steady speed and load conditions where the batteries do no help as much.
A hybrid will get better mileage in the flats than the hills, since it is subject to the laws of physics just like any other car. A car that gets better MPG in the hills, or in stop and go, is a perpetual motion machine. Because of inefficiencies, you capture less than 100% of the available energy of a hill or stop, and you deliver less than 100% of what you actually captured when you accelerate again. You would have to capture and deliver more than 100% of the available energy to do better than the car in the flats at the same speed: perpetual motion. The reason stop and go MPG seems so good is that the average speed is very low (10mph or less), but if you drove that actual average speed steady, you would do better than the stop and go MPG.
"The hybrid that is stopping and starting would not do well due to ICE having to kick in more...coasting around at 20 mph is more desirable...remember though, that the the 31 EPA mpg refers to start and stop at low speeds"
Yes, 31 mpg for slow stop and go, but better for slow steady driving like highway traffic where you don't have to stop, or at least not quickly. This is why people are observing mid 30's under certain conditions, better than EPA city. They see this when they drive slow, but without much stopping, only coast down.
In order to get the best reception it is best to keep the antenna on the i605 extended. There is a nice little compartment in the 400h center console where you can stand the phone up while driving.
Yes. That is one of the poor decisions that Ford made with the Escape Hybrid, they use a driveshaft from front to rear to provide mechanical 4WD. Even with a torque split device, that stuff is always turning. The electric only rear hurts 400h off road capabilities, but I hear the Hybrid Escape is no off road star either, despite shaft drive. Another advantage of electric 4WD is the ability to capture braking energy from all four wheels, and balance the front to rear brake forces. The rear brakes don't do half the work, but maybe 1/4? That makes it a more efficient hybrid.
Here in Florida, I can't remember ever seeing an open moonroof on any type of car. It is a place where water and/or heat may leak into the car. It is heavy, and worse, the weight is at the highest point in the car, reducing stabililty. It reduces headroom. It is another maintenance item.
I understand that in other parts of the US it may also be a valued feature. I would really like to know if it is something worthwhile. I am on the list to buy a Highlander hybrid and am trying to decide whether to get the option package or wait for the base car w/o moonroof. I believe 100% of Lexus hybrids have moonroofs so it should be a fair sized sample.
It is not quiet enough to listen to classical music. My wife has one in her 1990 LS400 that has not been opened 10 time in 16 years. That includes to let the light in. That $1400 option is worth about $400 in 3 years. I see the new LS430 it is standard equipment. I think it is that it looks cool. I would not have paid extra on my new Passat if it was not standard EQ. If it is near worthless in San Diego, I would say that is true in most of the USA. If it would open up far enough to stand up and shoot rabbits racing across the desert it may be worthwhile.
Short term results such as this are strickly the result of having previously stored energy in the batteries. Eventually that energy must be replenished and the ONLY way to do that is via the consumption of gasoline. Even the energy recovered via regenerative braking is the result of momentum created by burning gasoline.
So, yes, the more times you brake, or coastdown the more often the battery will get recharged for "free". On the other hand if you are on I5 from Seattle to Portland, a reasonably FLAT route, with light traffic (it happens) and with cruise set there is very little opportunity for the use of regenerative effects to recharge the batteries.
Even at a constant speed the electric motor that sets the CVT ratio must always be energized. And given that "constant speed" is non-existent anytime you accelerate even slightly the second electric motor will kick in to prevent the ICE from having to "rev" up.
That's why the city MPG rating is always better than highway, highway cruise ofters very little opportunity to recover inertial energy via regenerative braking or simulation of engine compression braking.
Suppose you start out with the computer reset and with fully charged batteries and drive slowly at a constant speed until the ICE is forced to kick in due to low battery charge. Since absolutely no gasoline was consumed up to this point what does the computer indicate for MPG?
Infinity?
Unless the computer somehow keeps track of how much battery recharge was "free" vs via the ICE it cannot possibly compute the correct MPG in the short term.
Absent this bit of knowledge, battery charge source, ICE% vs regeneration%, It is impossible for any of us to compute average MPG except over several tanks of gas, maybe even 10.
As you say, "...everyone has their needs." Guess that's why they're optional..
In an SUV, that's less of an issue for me -- not too tall -- but in a car, it was a dealbreaker for me and the Mazda MX-6 with the gorgeous body.<