Hey guys i have a 1993 SC that i just bought and is suppose to have a fresh motor 10k ago.The oil psi dropped on it so i hooked up a mechanical gauge and it has 52psi when running it hard.But it only has 15psi when idiling(the electric gauge was falling to 0).Is this too low?If so what is the possible cause.Oil psi was fine until i changed oil.I used Mobil1 extended life synthetic,Fram filter and Lucas oil Stablizer.Any help would be appreciated.