Did Toyota ever change the MPG computer to read a more true and accurate reading. It seems that the newly manufacture Prius are closer to the mark than the earlier ones. For instance I purchased our Prius in May 2009 and now we are approaching 29,000 miles and the MPG guage is consistently off by an average of 3 MPG. i.e the guage reads say 55 MPG you than calculate by miles driven and gallons of gas used and it calculates to 52 MPG. It as never, under read, alway over estimated. alfon
Well ours is either a Feb2010 or March build (can't recall what the door sticker read) and we bought it in April, have 5400kms (~3400miles ). We are on our eighth tank the average differance between the computed and the calculated is 6.5% - car reading high of course. The difference in your example is 5% which isn't to bad especially if it is consistent. I've been as high at 12% and as low 1.5% so I would say the problem (nuisance really) is definitely still around. I don't find it that big of a deal more of a letdown. When you pay the amount of money you do for the car it would be nice/expected for it (and the DTE) to be a bit more accurate. No vehicle is without problems and if these are the only ones I run into with the Prius I will count myself fortunate. It is a fun and enjoyable car to drive.
My car has a build date of 07/09 and and error of 5%. I have checked it on long trips using many tanks of gas which tends to cancel out the "gas pump errors" and the error is real, Cons display reads 5% high. IMHO this is not an engineering error, Toyota engineering is to good to make such a stupid mistake and not correct it. It is done on purpose, probably under orders from high level managers. The reason is obvious, most people will not calculate their mileage and just accept the Cons reading and the error makes them think they are getting better mileage than they really are. If you call Toyota to complain you will get the "Oh, we have never heard of that before" line. It's a bit dishonest, but car companies tend to lie to their customers frequently anyway, not just Toyota, all of them. So we live with it and at least it seems to be a consistent error so you can quickly calculate your real mileage.
It is all software. I am sure they can update the firmware to make it like the newer ones. When I took it in for the brake recall the the software changed so I could run the battery a lot lower then before.
Do you have any details, say something on the work order, that we could use to check our vehicles? Bob Wilson
mine has a build date of April 2009 and i think i got mine around the same time as Alfon but i rarely am anywhere near "only" 5 % off. check my sig. for me 5% would be considered a Bullseye mine is more less consistent. as far as DTE being accurate, i knew that it would not be. people are too stupid. if Toyota did not build in a fudge factor; iow, DTE = Zero means we still have 30+ miles left would have too many people sitting on the side of the road out of gas.
Has anyone ever heard of or witnessed a vehicle from any manufacture that displays accurate MPG's? I haven’t.
I checked my Gen2 (2005) Prius a couple of times (consumption display vs pump mileage) and I think it was pretty close, which is why I was a little surprised that Toyota had built an error into this one. I have a friend who is a sort of hypermiler with his Hybrid Camry, I'll ask him. I think the one on my 3 series was optimistic but I always thought that was because of the tires. I understand, from other forums, that Honda's may have the same type of optimistic consumption errors that we do. Maybe it's an "industry standard" .
My ex-girlfriend had a 2006 Honda Civic Hybrid. The MPG guage always under estimated. For instance, if the guage read 51 MPG the calculated MPG would be 52 to 53 MPG. alfon
