I'm just curious about this...my last Jeep didn't have an oil pressure gauge. The jeep that I recently purchased does. As soon as I start it up...even if it's 20 degrees outside, oil pressure is almost exactly 40 psi. It doesn't change once it gets warm, nor is it any different when I start it after it's been in the 60 degree garage. It does go up (slightly) when the RPMs increase, but never more than about 45psi. Is this normal? Shouldn't there be some difference between hot and cold??