I looked at some supercar spec and their tire size and I found that for rear tire they are all super huge which is very understandable but for front tire most are 235 and 245 and not too many are larger than 245. So what is the rationale behind this not too wide for front tire thing? Everything else the same, isn't it the wider the better? What is the good and bad for a very wide front tire?

Allen

 

its not neccessary the wider the better, but widder tire usually give you a better traction, but it also slows you down on the straight.

it really depends on what car you checked, if the tendecy of the car is toward oversteer, the stagger(ie small tire up front and fat tires at the rear) setup is very understandable.

 

i might think another reason is because the fron tire needs to turn, so 235 could be somewhat the largest you could go without rubbing unless you have adapters or spacers...

 

As has been mentioned, the wider the tire, the more aerodynamic drag. In supercars, some of the bragging rights comes from the top speed capability.

You also have to remember that many supercars have a mid mount or a rear mounted engine. There is much more weight in the rear and you need extra rubber to keep things from getting too squirrely (spelling?).

 

Wrong.

275s fit beautifully... even VERY lowered.

 

Take Ferrari Modena 360 as an example, it is a V8 with 400 hp capable of 0-62 mph 4.2 sec but it only comes with front 215/45-18 (rear 275/40-18). Doesn't 215 just sound very small? It is smaller than what everyone have on this board.

Allen

 

I run 245 all the way around on my Z.

 

You have to remember what al503 said about weight distribution. Mid and rear engine cars typically have much smaller tires up front (a la 360, nsx, and 911). Another reason for smaller front tires has nothing to do with performance it has to do with liability. Smaller front tires tends to induce understeer...a safer condition for the average driver than neutral or oversteer (no OEM wants to build a car that a lawyer can accuse of intentionally making it dangerous).