I went 10K miles on oci using Mobil 1 and a Purolator Knockoff, no problems. Changed the oil at 91K miles with PureOne Filter and Quaker State 5w-30 Synthetic. I am going to check this one out and see if it will run out to 15k before another oil change.
Actually, the Mobil 1 could have seen more miles of service, I just thought that it would be better to change the oil and put the PureOne Oil Filter in place of the Purolator Knockoff.
With Mobil 1 Synthetic, I did not have to add a drop of make-up oil at all into my 2000 Frontier.
Mileage was fantastic over 27.5 miles per gallon in city driving, except when I went to the Texas coast to buy the reformulated junky gas in Galveston/Houston area, which caused it to drop to 17.5 miles per gallon...