I bought my Dads 1988 suburban with 150,000 miles on it and he only used mobil dino oil and changed every 3,000 miles. I did the same thing until MC5000 came out many years ago and now I change it every 5,000 miles. Today this suburban has 288,000 miles on it and it uses maybe 1/2 a quart in 5,000 miles, runs like a champ, does not have any lifter noise, knocks, pings ect ect ect! This is the original motor and it has never had to be taken apart for anything. I drive this truck hard, towing a 30' travel trailer, 4x4ing in mud and trails, snow plow with it!
I used it in my Wifes 2000 Bravada since we got it but now I am going to switch over to Mobil 1 EP just because she drives 25,000 miles a year and change it every 6 months. Her truck does not use a drop of oil in 5,000 miles so we will see how the Mobil 1 EP works in a long term test because that is all I am ever going to use in it from now on. It has 110,000 miles on it right now. I will post back in 4 years when it has 210,000 and let all the oil guys know if it is burning any oil...lol!