I just ran a compression test on my 96 Sentra with 120k miles. All of my readings were between 145 and 155 pounds for all four cylinders. All tests were done after I put a squirt of oil into the spark plug hole. The increase in each cylinder after the squirt of oil was approximately 10# per cylinder. I read in service manual that I should be getting a min of 171 pounds and a max of 199 pounds. Whew! These numbers are very high and I am way out of the ballpark. The car runs great. So.... how close am I to an overhaul?