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I have a feeling that I may know what causes your low fuel economy. You wrote...
I have had the car for less than two months and have put on 1600 miles to date.
Any information will be greatly appreciated.
In 60 days this is about 30 mi per day on average. Can I guess that you take a few short trips each day locally?
If so, this is the single worst factor in destroying fuel economy. No one will ever tell you that but every vehicle on the road, hybrids included, suffer from this characteristic of internal combustion engines. Your Prius and all other hybrids are still essentially ICE's. Short trips are death on fuel economy. The second worst factor is bad weather.
As a comparison if you were in a normal non-hybrid 4c ICE vehicle such as a Camry, taking the same short trips, your fuel economy would likely be in the 22 mpg range ( CR estimates ).
How would you describe your typical 30 mi drive each day
No of trips / day....
Distance / trip.....
Speed............
% Hwy driving....
% City driving.....
weather, temperature.....
terrain ( flat, hilly? )...
No. of passengers? Cargo?....
Can you provide this easily?
These are all the factors that the EPA fails to mention other than the disclaimer 'Your mileage may vary'.
Mine for example is:
150 mi daily commute
85% Hwy @ 60 mph
15% City @ 40 mph
flat terrain
good weather
one passenger, no cargo
51 mpg over the last 15,000 mi.
Great Forum.
I'm glad to get 45! I attribute this to keeping the speed below 40mph as much as possible. I did not change my other driving habits for this experiment.
Unfortunately, my drive to work has about 4 blocks at 30mph, 10 blocks at 40mph and the rest is county road at 55mph (some days 65) for a total of about 13 miles. In this area, if the speed limit is 40, EVERYONE goes 45 (or more). Thus driving the Prius below 40 will eventually cause an accident and is unacceptable.
I'll try some more experiments and post again later.
I agree, this is a great forum!
I own a 2003 and am getting 51 MPG. From what I have experienced with this type of car you have to drive it a little differently that a normal car, if you want to maximize the MPG. From a complete stop, ease into it, and whenever you have a downhill, let off the gas. Let the screen guide you. If you tweek little things about your driving, you will be getting 50-55 in no time.
From all I've heard, I'm doing everything right and I'm getting 45mpg - at best! I'm not carrying heavy loads, I ease up to speed at the starts and let the motor generate power as I approach a stop. I keep the speed at the speed limit (when I feel safe in doing so). I have the tires at the inflation numbers on the chassis (I've heard to increase the pressure to 42front/40rear but I'm reluctant to do that - it's not a recommended Toyota practice and I'm trying to keep it "official".)
Pretty soon the sales guy, my wife and I are going for a drive. The sales guy says he can show us a few things that might help...
My plan: Zero the trip counter and let the sales guy drive. I want to see him get over 50mpg on that guage. Then my wife and I will drive and let him critique our style.
I'll post again when I have more news.
1. This is a Texas summer, so sometimes I drive with a/c and sometimes without. I notice a big difference in the MPG; I get about 52 without the a/c and 45 with it turned on. I have seen in this thread that others have noticed a 5 mpg difference, but have read elsewhere on the Internet that it is negligible. For me, the difference has been very noticeable.
2. My tires were inflated to a pressure between 25 and 30 psi when I bought the car. I increased them all to 42psi and I noticed a slight mpg improvement and slightly better handling.
3. You do not have to drive less than 40mph to get these excellent mileage numbers! Most of my trip to work and back home is on a highway, and I drive around 63 to 65 mph. My mileage is slightly higher in town, but the difference is very little.
4. My rough estimates indicate that the car's computer is close to accurate on the actual mpg.
My automotive budget is lower than for most people; in fact, the 5-year-old Prius is probably the newest car I've ever bought. The inside space feels midsize, more than enough space for my family of four. This is a cool car!
How many miles are on your Prius?
Does anyone remember reading any studies on the mileage effects of AC :confuse:
This is a very interesting page filled with PDFs which indicate good performance in regard to HEV battery life.
See this one in particular:
http://avt.inel.gov/pdf/karner.pdf
One of those PDFs, maybe the last one, has a few statements about the effect of A/C on the Priuses. Seems like it took a substantial hit.
I see there has been a good improvement from Generation 1 to Generation 2 Prius in MPG, and that the AC will take about 10 MPG away from you....pretty cheap price not to melt, imo.
Mike
Knoxville, TN
Good post and welcome to the Forum. We would never accuse you of prevarication on this forum. We all get along. Keep us posted on your Prius.
In a few days I am going to pump up the tires with Nitrogen, and I may try to jerry-rig a EV switch, and hopefully I can get the mileage to 50+ consistently. Without it (EV) the engine goes on too often, even with battery full and car going slowly.
The engine, computer controlled, making thousands of calculations per second, turns the ICE on exactly when, and runs it just as long, as it should.
Certainly it is your car, and you can do with it as you wish, but I urge you to consider all the ramifications.
Good advice. Dealers are always looking for ways to get out of warranty repairs. Don't give them ammunition. Be happy with your 46 MPG. That is very good. I would imagine you are using the AC and it will require the engine to run more also.
I like the idea of a switch too, but the others are right, connect a switch = void the warranty!
And I bet Toyota is not going to give you a switch just because you ask for one. They THINK their computer program is smart enough to adapt to the speed being driven. Unfortunately, I think they are wrong, their on-board computer program is good, but it could be improved a lot! The engine runs entirely too much for me! I have noticed many times that the engine is running on a flat road with the battery mostly charged and the speed below 40. The motor should be maintaining the speed and the battery allowed to power it. But instead, the engine starts...
And I doubt any lawsuit over the switch being installed would result in Toyota winning, because the EV mode switch is
STANDARD EQUIPMENT FOR ALL PRIUSES EXCEPT NORTH AMERICAN MODELS.
This factory option is currently not available for buyers in North America although the programming for it is still included in the computers which control the hybrid system. This kit allows you (in just a few minutes) to activate the electric feature of your Prius and drive for short distances. The software already present in the car will automatically restart the engine when the battery needs to be recharged or if you need to accelerate quickly. The electric only feature can be turned on and used up to a speed of around 34 mph at which time it will automatically turn off and the car will operate as usual.
So my guess is that it would NOT void the warranty if challenged, because Toyota thinks the rest of the world is "smart enough" to use the EV mode button but we dumb North Americans are not? Puh-Leeze.....
The simple solution would be for you to present, here, a letter, or executive name, from Toyota saying what you have above. :P
There won't be a lawsuit, and it doesn't concern dealers, for they are more than happy to perform warranty repairs. They account for a substantial portion of any dealers bottom line profits. It matters nothing what Toyota does in other countries, except to you, evidently. Toyota will just deny to pay any dealer because of the switch effecting....God only knows.
Maybe you could put as much effort into finding out why that switch isn't provided in the United States. Something tells me it has nothing to do with judgments about the intelligence of the driving public here, and more to do with a technical need.
What does it matter? 4 wheel disc in Europe . EV mode is built into software, just disabled. Ever seem multi-iuser licenses in software, whereby a key disables features not offered or features you don't pay for? Nav not offered in Canada, but DRLs have always been required.
Business, marketing and requirements decision. Doesn't always make sense and doesn't have to do with intelligence or technical needs.
Also it you look back through this thread and other Prius threads there are many hacks and add-ons available for the Prius. The hacks are not intrusive and not permanent. Therefore, they can be removed without evidence. Without evidence the car owner can not be proven guilty. Therefore no puntititve or compensatory damages.
LOL,
MidCow
The software already knows how to handle it, therefore it cannot damage the system.
Go for it modders !!! :shades:
Installing the switch doesn't sound very smart to me.
So, it is always okay to lie, especially when for monetary gain :confuse:
I gotta go lay down...........
What I said is that "toyota really has no grounds to deny a warranty claim for someone who installs an EV mode switch if the HSD software is already CODED FOR USE WITH an EV mode button and they just "left it off" the North American models."
Hundreds of Pruis owners have done this mod. It's not a big deal.
Hundreds of Pruis owners have done this mod. It's not a big deal."
Toyota provided a warranty book for your US MODEL Prius. The only things they are legally required to honor are those things specifically covered.
1. If you modify your vehicle you will probably void the warranty. If this language isn't in the fine print of the warranty, then Toyota is an idiot company. The first time you showed up with a bad battery, or possibly any problem, they could legitimately deny you coverage. Auto makers have been covering (and denying) warranty repars for a long time. It wouldn't be much of a court fight. 1) Did the owner modify the vehicle? [yes] 2) Does the warranty prohibit this? [Yes] 3) Was a copy of the warranty provided with the vehicle? [Yes] Case dismissed, with prejudice.
2. You do not know if the US version has the EV modules in the software. It may well have a completely different version, without EV. Since there is no factory EV switch, I would be shocked if Toyota left in this orphan computer code.
Here are some exerpts about the UK EV Mode:
"EV Mode EV mode is apparently not available in the US, for reasons I suspect have something to do with product liability. As evidence, the following quotes are from the UK version of the Prius Owner's manual.
* 'In the "EV" drive mode your vehicle runs like an electric vehicle, only using the electric motor....'
# 'CAUTION The driver should pay full attention around the vehicle especially when it is driven by the electric motor (with the gasoline engine stopped). People in the immediate area might misjudge the hybrid vehicle movement based on the absence of the regular engine noise.' Not only in bold, but inside a black border!
# 'In the following conditions, the "EV" drive may be automatically cancelled....
# The hybrid vehicle battery assembly charging level is 2 or lower. The vehicle speed exceeds about 45 kph (28 mph). The accelerator is depressed strongly or on the slopes.' [The EV range] usually ranges from several hundred metres to 2 km (about 1.2 miles or less) ....'
# '... frequent use of the "EV" drive mode may worsen fuel economy.'
http://tinyurl.com/my3en
IF you have problems (which I doubt - it's a Toyota for heavens sake!), you WILL have to take them to court if you want warranty coverage. So you WILL be supporting lawyers! Good luck on this one. Toyota is a billion $ company, they can afford the best lawyers. Usually they would win. Personally, I couldn't even afford the court costs (which you would be "awarded" if you lost)!
According to reports I've read, you will not save fuel, you may end up using more, as there are losses in the conversion of fuel to battery charge (20-40% losses). The only benefit I see is a little convenience. If you just want to move the car a short distance using electric only, use very little throttle. It will usually stay in electric mode for up to 30 sec. or so. Unless the battery is down a bit on charge.
The software module is in the North American cars. If it wasn't the switch wouldn't work. Even with the switch activated, the car will still engage the ICE when necessary. It just does it later than normal.
The Prius, with or without the EV switch, is a -gasoline- powered car. All power comes from fuel burned in the ICE.
Now you -can- do a "plug in conversion", where they add a lot more battery and a charger. In this case you would obviously void the warranty, but you could drive perhaps 10 mi on battery power only (I haven't checked lately on their progress - check http://www.calcars.org/ for info on this project).
Feel free to do what you like. Lots of folks have added the switch. Some remove them before letting the dealer see the car, some do not. Just don't be in denial of the consequences.
Is it a lie because a stupid, incompetent driver causes a wreck? Well yes, the liability is on the driver not the car.
Cheers,
MidCow
P.S. - Don't use your lawn mower to trim the top of your hedge.
FUD "The sky is falling! The sky is falling" -- Chicken Little
Don't believe every rumor you read or hear,
MidCow
MidCow, you ususally get the point faster. The EV switch is not approved for the US model Prius.
Toyota does not allow EV switches in the US version, and installing one is putting a non-Toyota-approved hardware modification on the vehicle. This voids the warranty, and opens the possibility that Toyota may not honor parts or all of the warranty if you have any trouble with the vehicle. The same thing is true if one tries to "re-flash" the CPU chip.
Hardware modification is not usually reversable, nor is a firmware mofication, e.g. flash.
The EV external switch is not really a hardware modifiation, but a software hack. ... okay, find the same software hack that enables the software feature...
probably up down down up rigth right left on the fuel display screen :P . That is not a hardware modification. Just wait until the hack is know then you would agree , not a hardware modification.
Either find a smart Prius owner out there or wait until they make a mnaul shift Prius and I enable the EV mode.
LOL,
MidCow
MidCow, if you can enable the sofware without a switch, then you are correct. However my understanding is that the owner is installing a hardware switch somewhere in the car. That is a hardware modification, regardless of what the switch does. They are also running wires from the switch to the CPU; those wires are not "virtual wires", they are hardware.
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They got into this because some people think the EV switch would improve MPG...
Note that others have reported the ability to put in as much as 12 gal. when empty and as little as 5 gal. It depends on the state of the fuel tank bladder and the fuel pump shutoff as well as the seal around the fuel pump nossle when inserted into the filler tube.
I suspect you will get much better results in subsequent fills. Please keep us up to date on your results.
BTW, short trips will kill your mileage. The car uses a lot more fuel for the first 5 mi. of driving as it has to warm up.
For the past 6871 miles my average mpg is 57, the trip computer varies between plus or minus 2mpg from my manual calculation. The bladder feature complicates filling it to the same level on each fill up without risking a spill.
My situation is such that I do much driving in PA, gas there averages 30-35 cents less per gallon than in Western NY(Buffalo,Rochester), so being the fuel miser I am, often find myself filling the tank with only 300-400 miles on the trip. I loose out on the 600+ miles per tank but i'm not complaining.
Allow the bladder to be broken-in more not to mention the rest of the vehicle and you should find 45-50 mpg depending on your trip lengths ( huge effect on FE ).
Also, MPG computation, for that short of drive, and that new of a car, wouldn't really be something you should put much stock in.
The Prius will beat your Passat mileage wise and will emit much fewer emissions doing it.
The Prius doesn't use the battery power much in moving the car in "normal driving" to get much of its' mileage improvement. It uses the battery mostly to recover the energy lost when braking, and to allow it to seamlessly shut down the engine at lights and stop signs and then get going again, only starting the engine once it is moving. That way it doesn't use the ICE (internal combustion engine) in inefficient "start moving" operation. Also, use of the air conditioner or heater will lower mileage as increased use of the ICE will be required. With most cars you don't notice this, but the Prius really shows you how much energy those kinds of things require because it is otherwise so efficient.
The main reason you don't want to use the battery power for major motive power is it's so inefficient to charge it back up - 50% has been quoted on the forums. This is a further 50% loss on top of the loss of the ICE converting the fuel into usable energy. So most of the battery charging is done with regenerative braking. Unless you stomp hard on the brakes, the braking you feel down to about 7 MPH is the regenerative braking, not "friction braking". The car does use the motor generators (MG1 and MG2) to help move the car, but it uses the two of them to convert the rotating energy to electrical energy and back only when it's efficient or necessary. For example, there is no reverse gear. The system uses MG2 to propel the car in reverse. It uses MG1 to generate power from the ICE to run MG2 if you back up for more than a few seconds. Yes, it does use battery power to get going from a stop. And it uses some from time to time to accelerate. It may even use it to propel the car when going below about 38 MPH if the battery state of charge is deemed high enough. It tries to keep the state of charge between 30% and 70%. It will not let it get below 20% or above 80%, to protect the battery.
It really is an amazing car, but it can't perform miracles. All power used comes from gasoline. It just uses it more efficiently than any other vehicle.
One important point is that you have to define what you consider to be 'City' driving. There are at least 6 types of 'city' driving that I can imagine immediately:
.. crawling out of Manhattan in rush hour at 15 mph; ( easy to get 60 mpg )
.. stuck on the freeways of LA or the Chicago Loop or the DC Beltway; ( easy to get 60 mpg )
.. rolling through a typical congested suburban mall area during the Holidays; ( easy to get 60 mpg )
.. cruising through a residential neighborhood on a Sunday looking at houses; ( easy to get 60 mpg )
.. speed-limited residential thoroughfares ( easy to get 60 mpg )
.. going from stop light to stop sign to stop light on your way home in your neighborhood ( very hard to achieve 60 mpg );
The common thread in all of the above is the ability, in your personal city driving, to keep rolling at a slow steady speed ( under 40 mph ) with a fully warmed up engine.
On my 75 mile trip home there is one stretch of 10 miles through a residential area where the speed limit is enforced to 'under 40 mph'. During that stretch of about 10 min I achieve 65-75 mpg every night. For the last 4-5 min of my trip each night I 'glide' much of the way through the local streets achieving well over 80 mpg.
A) Fully warmed up engine
slow steady speed under 40 mph
c) little or no pressure on the gas pedal