Had the dealer replace the OEM Kenda rear tire on my 2012 RT today. Replaced it with the Kumho Esta AST. Here's my question: On the sidewall of the Kenda it states 30 psi max pressure and the owner's manual recommends 28-30 psi. On the sidewall of the Kumho it states 51 psi max pressure. Do we still run it at 30 psi even though that would be 11 lbs under max pressure? Would 40 psi for the Kumho be too high?