should we use different tire sizes for front and rear??

[vinit]

I was told by someone that front tire and rear tire should be different in width.Width of front tyre should be less than the width of the rear tire.Will it be good or not?

[SMN]

Design judges often say that the rear tires should be wider if there's more weight on the rear wheels.

One way to see this is that the energy which heats up the tire will be proportional to the weight on the tire. So having 6" tires at the front and 7" tires at the rear would match a 46:54 front:rear weight distribution. Some think the rear tires should be even wider to account for rear wheel drive.

On the other hand, the average weight distribution of top 10 teams is 47:53 yet most of these cars have the same tire width front and rear. Off the top of my head I think Munich is the only top 10 team with wider tires at the rear.

[C.Zinke]

It really depends on the compound you are using. Hoosier tires have a wide temperature range, within they can be used. If you have a compound that has a smaller range you really want to use different tires. The Continental tire for example was of this kind last season. It will be different in future but this was the reason why we used 6" at the front and 8" at the rear in the past. With a weight distribution of 56% rear we still had much higher temperatures at the rear. Even with the 2007 car (51%) we had 5-10°C higher temperatures at the rear. Another problem could be caused within the warmup of the tire. The goodyear is really bad within one or two laps. You would cause some understeer in this case, because the rear tire will be warm much quicker.