[RedDevil]

Originally Posted by Xusi

But are all of you 100% sure that tire pressure doesn't affect grip? Anyways, I've read that tires with high pressure tend to wear down faster from the centre than from the sides. Do you strongly recommend me inflating my tires way further than those recommended by the manufacturer? (I think maximum PSI for my tires is 50. Must check).

It's quite strange that I don't lose any grip with a higher tire pressure.

So, what pressure would you recommend me, if my car weights a total of 1370 kg + 55 kg (me)?
Keep in mind that sometimes I'll carry up to 5 people + charge in the trunk (+350 kg)

I'm sure it does affect grip, in a positive way.

Wear should be even with modern radial tires, where the wires in the carcass are evenly distributed over the track width.
It would just wear slower as the thread bends and scrapes less when it hits the road.
My two sets of tires (summer and winter) have worn evenly at 40+ PSI, with lots of thread depth left after 45.000 miles combined.

When you distribute the same weight over a smaller contact patch, that patch gets pressed into the road deeper, making it harder to slide.

Best pressure is up to you. The further you go the better it gets BUT the improvement recedes quickly.
Going from say 30 to 40 PSI can give you a 5% gain in overall efficiency.
Going to 50 PSI would only add 1% to that, and another 10 PSI would only add 0.1 % or so. Comfort and road noise may increase at those pressures, so that would be a clear sign to take it no further.
Max sidewall is another logical boundary. While most tires can handle way more than that you'd take it outside its intended use.

Whatever you do take small steps and check the tires after airing up, and again some time later. If a tire deforms it has been damaged and needs to be replaced asap regardless of pressure.