stone150

well reading this post makes me feel allot better. Ive got 135K on my 01 silverado with the 5.3L last oil change using mobil 1 (5000k miles) i was down about 1-1.5 quarts. I was getting concerned as my exhaust pipes are black and the wall on my garage has two black marks from the exhaust. But I drive that truck very spirited (allot of pedal to the floor) and I don't have cats on it.