re: OB mechanic opinions.

3000 mile recommendation is an oil company driven directive. If we all did that over the standard 5000 miles back in the 70's 80's and early 90's Oil companies could sell about 35% more motor oil in a year on avg. Basically driving up sales and profits. Oil tests on modern natural oil compounds are showing your high end motor oils like Castrol, Pennzoil, etc. types do not start to show any beginnings of break down before about 7500-8500 miles. And most all of your synthetics show absolutely no breakdown or loss of viscosity before 10K-12.5K miles. I have never changed oil in any vehicle I owned before 7500 miles. Never any motor issues and traded in or sold many vehicles with more than 250K to 350K miles.