I must admit, I barely if at all notice a difference when I change the oil of my cars. My CL Valiant went through so much it was getting one anyway with all the replenishing it needed. I even discovered it had the wrong size air filter for four years, leaving a 1 inch gap for unfiltered air to come in over the top. The Borg Warner 35 auto transmission started giving out by the time we sold it for spares while the engine was still pulling well.
