I have a 99 996C4. its is a pain to get tires for this thing and i need to know the max difference the front and rear wheel diameter can be.

I was told that stock this car had a -.4 difference between the fount and back wheel with the back being smaller.

My summer tires have a .2 difference with the back tires being larger

does Porsche has a specific range that is acceptable? in its 4 wheel drive cars?

anyone know where i can find this information?