Hi, At 2000 rpms to 4500 rpms my oil pressure stay at 40-43psi and when I back it down to idle after a five minute run the oil pressure drops to 10 to 15psi. Does any one have the factory oil pressure specs? The oil I am using is Moble one synthetic 15w-50. Is the oil pressure ok and is this the right oil. Thank you for your help.