I have a 2001 GMC extended cab Z71 with the 5.3 Vortec. I bought it new and have ran Valvoline 10w-30 till 75,000 miles then switched to Valvoline Max Life 10w-30. It holds 6qts and I replace 1qt with Lucas Oil Stabilizer every oil change. I got 175,000 mile on it now and its using a little oil now around 1 or more quart's between oil changes. I run it with and without the stabilizer and no difference in the oil consumption. Is there a better additive to help that I should try? Should I change oil brand? Any input is appreciated. Thanks!