that is not true...the acceleration goes down due to less sidewall flex, but if the tire has the same outside circumfrence, then it will have the same revolutions per minute.....

 

17" diameter = 25.681 = circumference of 80.67
18" diameter = 25.303 = circumference of 79.49

So you actually have a slightly dmaler circumference with the 18" than you did with the 17". But it's barely noticable as it is just over one inch. As stated before, you do lose the sidewall flex. Technically you would also lose gas mileage due to the smaller circumference, but given how they are so close, you wouldn't notice the difference.

Basically, this goes back to what Twister was saying about cornering and sidewall flex. Personally, looking at the numbers I don't think it will make a huge difference or even be noticable. I would go with whatever ones look better

 

saying anything about lowering gas mileage makes me cringe.
i have a v6 and am only getting 200 a tank. thats like 13 miles a gallon. and its hard for me to afford gas when its $3.15 a gallon.

 

okay, and?

 

Lower profile tires will give you less traction though so that might be what you are thinking of

 

Well if you read the rest of the thread, I explain what that means when I finally get the exact specs of what he has and what he wants.

 

I have a issue concerning rims and tires that I can't get a straight answer about! I have 235/55 17 and I want to know if those tires wilo fit on 17 X 9 rims?! Also what does back spaceing refer too?

 

a 235 is narrow for an 8 inch wheel...backspacing is he distance from the back of the hub of the wheel to the inner lip of the wheel, so if the distance from where it bolts up to the inner lip is 5 inches, the backspacing is 5 inches, the larger the backspacing, the further in towards the center of the car the inner wheel edge is.

 

So you are saying that those rims are not going to fit my tires?!

 

lori, I have 245/45/17's on a 17x8, I wouldn't want a wider wheel for that tire. As for tires, they wear out, wait until you need new tires.