Having a discussion about extended OCIs with a friend who is a crack mechanic. Seriously, he's probably the most sought after mechanic in the area and has done a lot of racing. He had two sweet '66 hemi Chargers...one to race and one to drive around to shows and on Sundays.
To paraphrase his argument, dirty oil is dirty oil. Even if using a high quality synthetic that may have a lot left to it after 6, 7, 8 thousand miles, once it starts to get dirty the best thing you can do is change it. Changing any motor oil after no more than 4-5 thousand miles (he uses nothing but Castrol GTX changed at 3,000 miles in his vehicles) is the best thing you can do for your car.
Opinions?
Mikep
To paraphrase his argument, dirty oil is dirty oil. Even if using a high quality synthetic that may have a lot left to it after 6, 7, 8 thousand miles, once it starts to get dirty the best thing you can do is change it. Changing any motor oil after no more than 4-5 thousand miles (he uses nothing but Castrol GTX changed at 3,000 miles in his vehicles) is the best thing you can do for your car.
Opinions?
Mikep