Gas Mileage/Tires

[mkosem]

Ok, I have made an observation. Previously, with my continental tires, I observed a maximum fuel economy of 30mpg. This was babying the car and rarely going over 4k rpms. Average day to day economy being 22-25mpg But now, with my Yokohama Avid V4's I've been getting consistantly higher gas mileage, topping at 33mpg on my last tank and 32mpg on the previous one. The contis had 30-32psi in them warm before I took them off to replace them. I'm curious, are the folks experiencing poor fuel economy all on the contis?--Matt

[ragingfish]

Fuel economy can definitely be affected by under/over-inflated tires...if the previous tires were not properly inflated, that most definitely can impact your fuel economy ratings!

[mkosem]

But the tires were pretty close to the recommended pressure(32psi). a couple of them were actually dead on.

[Kissfan79]

I generally keep my Goodyears at 35/36psi. I have noticed that I wll get an extra mile or two this way. My drive to work is about 47 miles one way on the highway though. Jim

[aggie_vibe]

Consumer Reports tested 'rolling resistance' and found a difference of a few mpg between the best and worst tires.

[mkosem]

I've got a 30 mile each way drive to work. about 10 miles of it is on twisty well paved country roads so I gotta keep the pressure at 32psi --Matt

[DavidPIL]

Hi mkosem,You said the conti's were at 30-32psi warm. The rating on the tire is when it's cold so you should check the psi before driving. I changed my tires from the OEM Dunlops to a much better Continental tire (ExtremeContact), I noticed the conti's I have are much more sensitive to temps. If I check them cold at 36psi, by the time I get to my destination which is about 35 miles away, the tires are sitting at around 40-41. But they are even all around. Also notice this change in temps. If I set em at 34psi when it's 20 degrees out, when it's 40, they're 36-37psi. Normally you can expect an increase of about 1 psi per every 10 degrees of air temp. It seems to hold true here. My old Dunlops didn't seem to be as accurate/sensitive to temps though. By the way things are with my Conti's. you were probably driving them 4 to 6 psi under, if you checked them after driving (warm) which would very much show up in the MPG and wear of the tire.Dave

[mkosem]

I dunno, the dealer claimed they set the tire pressure correctly when they alligned the car in december. But I find that my dealer is not so good.but 8-11mpg is a huge difference. I have been driving the car like I stole it since I got the new tires. Not babying it at all. I'd imagine I could hit the EPA specs if I drove it easier.--Matt

[johnsoax]

Tires have to sit for at least 4 hours before you check the pressure. Back when I had my old car and lived in an apartment (didn't do my own maintenance) I would tell them not to check the tire pressure because too many times they were letting air out of my tires to bring them down to 32psi. But they should have been above 32 because they were warm.

[joatmon]

Was the alignment done at the same time the tires were replaced? eEpending on how far off the alignment was before, getting that corrected could also account for an increase in mpgs

[syclnjr]

I think that you are all right about the tire issue, I just got my vibe about three weeks ago, as in my sig you can see what it is. but anyway the demented realization of the dealer the tires only had 22 psi in them when I bought it and I didn't notice anything until a few days ago. I only havea 1,000 miles on my vibe and I travel the highway alot. that being said I was only getting about 220 miles to a tank of gas. I put the correct air pressure in the tires and I noticed yesterday that I have gone 100 miles on just a 1/4 tank I think that is one hell of an increase, which makes me love my vibe so much more especially getting out of my Jeep Grand Cherokee with a V-8 and going through 40 bucks a week in gas. There is my two cents, later

[johnsoax]

When the weather is warm I usually get 200 miles for the first half tank (100 per 1/4) and then it drops a little more for the last half, but usually is about 75-80 for the 3rd 1/4. (Twice I have gotten 100 miles per 1/4 all the way, 419 being the best!)