Does Mobil 1™ or AMSOIL provide the best protection for longer drain intervals?

“I read on the Internet that AMSOIL has interval change of 25,000 miles and say they back it up with oil testing done on fleet commercial trucks. What is your opinion how Mobil 1 vs. AMSOIL compares? Can you quote if testing has been done and which is better? I would really like to know who makes the best oil and why Mobil™ says to change oil at recommended intervals by the manufacturer. If Mobil 1™ Extended Protection is used, the change interval is still only 15,000 miles compared to AMSOIL saying 25,000 miles. I currently use Mobil 1 in both my Toyota Tundra and 4 Runner, but AMSOIL claims of 25,000 miles with fleet testing gets me thinking maybe I should change to AMSOIL. Your honest reply citing professional standards used would be appreciated by many of the public (i.e., ASTM). I really would like to know who has the best protection and why. Your reply is greatly appreciated.”

Greg Galbreath, Palmdale, California

Answer

We certainly can’t speak for AMSOIL, but you can see the kind of testing we put our oil through by looking at the Las Vegas field testing we completed with Mobil 1™ motor oils in Las Vegas taxis. In addition, Mobil 1™ synthetic motor oil is chosen by more car manufacturers as factory fill in their vehicles than any other motor oil. We also are approved against the latest industry standards and appear on the OEM approval lists of all the major manufacturers. Mobil 1 synthetic motor oil is all about protection and helping to extend the life of your vehicle.