I run 38 front, 35 rear on my Ecsta 711s. Mainly because they feel softer and less responsive than the stock Dunlops even though they are 205/40R17. I was proven right when I hit a pothole at the wrong angle and gouged the side of my rims!!! (bang)
When you go to a skinnier tire you hafta run higher pressure to compensate, because the tire has a lower load rating at the same pressure. Its like on my jeep the stock tires called for 32... but i ran 35" tires at 23 psi and they wore perfectly.
If you are running a 40 series tire you should be 38-40 depending on the tire.
depends on the condition and what you're using the tires for. daily driving..stick to around 35-38psi. I run mine 40 all around cause I usually go on spirited drives and i don't want sidewalls folding.
