I own a 2003 Chevy Silverado with a 5.3 liter engine and my oil pressure gauge moves a lot durring driving. It is a 40 psi at idle 50-60 crusing at 60mph and when I floor it it goes up to 75-80psi. My friends 2002 Ford F150 with the 4.6 liter engine does not move at all! The gauge does not have any numbers, just a high and low and his sits right in the middle all the time. Why dosen't the Ford move? Why is this and is this normal? My 2002 Camaro also fluctuates a lot also. Is it good to have fluctuation through out the rpm range?