I just bought a carthat has 20 inch rims with low profile tires Whats the reccomended tire pressure for low profiles? Its p255/35ZR20. Is it the same 30 psi as regullar tires?

 

Max tire pressure should be on the side of the tire. That also takes in to account that the tires are being checked while cold. So no need to worry about tire pressure going beyond the limits when hot.

 

i think i foun where it says max load 51 psi. doesent that seema little to much?

 

No. There is a lot that goes in to tire pressure, contact patch weight of car etc. If in doubt call (e-mail) tire manufacture and they will give you the info you need. That's the simple way. Remember these tires are made for handling and you will not get the wear out of them as a normal profile tire.
Good luck.

 

If i buy 2 new tires, is it better to have the newer tires on the rear or front? I can never remember. Its for a RWD. and is it different for a FWD?

 

that shouldnt happen .. rotation is meant to not allow that to happen.

But if it happens, on a car with a normal loads, I mount the best two up front since they do something like 80% of the stopping. That doesnt apply if your car has fatter tires in the rear.

If driving in snow and ice, the rule of thumb for the best tires, changes to the drive wheels.
regardless, the front tires wear faster and they will catch up in wear

 

Low profile tires generally have a higher standard pressure, due to the fact that they take more load on a smaller sidewall and greater tread surface area.

If the Max Load for the tires is 51psi, I reccomend about 45-48psi COLD. That means park the car for the night, then drive no more than 1/2 mile to the nearest air compressor, wait ten minutes, and FINALLY check the pressure. If you inflate to 45psi when the tire is warmed up, it will drop when it gets cold, because hot air expands more, and you have an inaccurate reading.