Tire Sizes and the One Inch Difference Issue
 

Hi All,

I replaced my wheels and tires about a year ago and when I did I remember the whole issue of maintaining the one inch offset between the front and back sizes was in my mind. The idea being that the one inch offset had to be maintained to ensure that the traction control wouldn't go insane. I hadn't seen anything on here to lead me to believe otherwise either.

Well, I replaced my brakes last weekend and something was nagging at me about the front wheels and I just woke up with what it was. I didnt' see any sensors on the front wheels for gauging speed. IF the front wheels don't have a sensor for gauging speed, then the offset issue is null because the only wheels that would need to remain about the same diameter would be the rear wheels!

Am I wrong? :confused:

Re: Tire Sizes and the One Inch Difference Issue
 

I can't answer the question, but I can add to it. I've asked this question here, the dealerships, the tire "experts" at chain stores and Tire Rack and while I don't think I've seen the answer here, all to the others say a flat out no....but when you ask why not, almost as though they are cloned they say "there has to be a reason with the computer". Yet the manual says to run the same size tires in the rear as the stock front for winter driving and says nothing about period of time.

Since I managed to find the Exclaim UHP's from Tire Rack at a price that when mounted was around 800, I didn't even worry about trying. But if these don't hold up much better than the stock Conti's, I'm going to be looking back to going with same size all around so I can rotate them....yes, that will mean the 255/35/19's will be gone.

Re: Tire Sizes and the One Inch Difference Issue
 

As we have seen with people putting these cars on dynomometers without the front wheels moving, the engine will begin cutting out (timing retarded) at about 4,300 RPM.

When we put these cars on a dyno that moves the front wheels like I did (Mustang dyno in all wheel drive setup), the rollers in the front drove the front wheels and we were able to do pulls all the way to redline.

So, there MUST be speed sensors on the front wheels.

Others have run 18 inch wheels all the way around as well as people running 20 inch rims all the way around.

As long as you maintain the overall stock wheel/tire height front and rearthen the TC should be fine.