2007 Camry Hybrid – last summer put 4 new Michelin tires on it. This was around the same time I moved to temporary digs in a really hilly part of Washington DC – ran the AC a lot – drove lots of short trips. Mileage as measured by meter in car dropped precipitously from average 38 mpg over the life of a tank to average 29-30 mpg.
Waited for fall and move back to suburbs – but no change when I turned the AC off and started more typical driving pattern.
Had car serviced (oil change, inspected a bunch of stuff for 60K) – put additive in gas tank in case there had been some bad gas – no change.
Winter came – no change, still getting 29-30 MPG
Mechanic looked again, saw nothing wrong, but did increase pressure on Michelins from 32 psi up to 36 psi… some change, now getting about 33 MPG
Realize that when fan is running and am stopped at a light, the fan is making a funny, “running rough” noise that corresponds to meter showing I’m getting 0 MPG, and burning fuel while at the light. Rough runing sound goes away when heating fan is turned off and mileage gauge jumps to infinity showing that am no longer burning fuel (which is where it normally is while idling at a light).
Is it the tires? To test the theory and decide the fate of the Michelins, should I pay $80 to mount my old snow tires that I know the car got 38 MPG on, even though its almost March? (and then another $80 in April to put the Michelins back on?)
Is it something to do with the heating fan?
Is it just a mid-life crisis for the electric motor?
Any suggestions?
Until more people own hybrids on this forum, real advice maybe limited. I would suggest you take your concerns to a prius/Camry hybrid forum, if you haven’t already.
I don’t know what’s wrong with your car, but I seriously doubt the tires are at fault. I’m thinking that the batteries may not be holding the charge they used to.
First let’s get a real measure of the mileage. Fill the tank write down the odometer reading and go about your business until it is time to fill up again. write down the computer’s estimate MPG. This time fill it the same way again, except this time write down the odometer reading and the number of gallons purchased. Do the math (subtract the last odometer reading from the current reading then divide the number of miles driven by the number of gallons needed to refill. Continue this procedure for at least three fill up’s
While those on board computers are good, they are not perfect as they are estimating results based on a few guesses. Your specific car and driving habits can result in some inaccurate results and you may need to do some adjustments so the computer can display a more accurate reading.
Unless those Michelins were specifically made for low resistance/high mileage, that could be at least part of the reason for the lower mileage.
The reason for MPG drop is your driving has changed.
The electric motor likely needs the gasoline motor much more for two reasons:
- the charge depletes fast and likely does not regenerate fast enough on hills
- hills
The tires may have a slight MPG influence but tops this only 1-3MPG from worst to best tires in terms of rolling resistance.
Andrew_j hit the nail on the head. I used to drive to Wash DC and VA for business on a regular basis and remember spending a lot of time stuck and/or moving slowly in traffic. 30 mpg under these conditions is actually pretty good.
Ed B.