Buy this stuff called tufoil. I have added it to every engine, not at every oil change, but several times a year...it contains additives that actually bond with the motor and helps reduce friction...I wouldn't have used it myself if someone didn't give it to me first, I put it in an engine that was using oil on a regular basis, used it for three oil changes, and after the third it was getting better...I was skeptical thinking it just gunk'd up the leak, until I had to take the pan and valve cover off and found it to be cleaner than clean, other than your normal buildup for a motor with 180k, but I was impressed. It also stopped my oil light from coming on while at idle...so it's good stuff, just expensive (hence why I only do it several times a year).
01 Xterra SE 4x4
Intake mod, timing belt, hoses, belts
PML, EFan conversion, shocks, 32" tires, and eventually UCA'S