Mobil M1 synth oil longevity?

[Damlaker]

If you read the article, they do indicate that the synthetic would appear to hold up better in colder weather. They also noted that since cabs are consistently running, their tests did not reflect "cold starts".

 

[IdahoDoug]

That taxicab test has been widely thrown out by knowledgeable people due to the biggest shortcoming - no cold starts and no extreme use. Synthetic oil's major benefit is in reducing cold start wear, which has been estimated to be over 50% of total engine wear. The test was a total setup.

To answer the initial question, do a search here with me as the poster and you'll find an oil analysis of my 94 with 140k miles or so of Mobil 1 performance, and also the testing lab's recommendation on how much longer I could leave it in. This would be the best proxy for you to use, assuming your engine's in good shape. I change mine at 6-8000 depending on how it works out for weather, trips, etc. I would not have a problem running it to 10,000 miles at all. I recently overheated my boat's 454 due to a wierd failure. It is totally fine after I pulled the plugs and squirted the water out of the cylinders. I always use Mobil 1 in it and in this extreme abuse it appears to have protected my bearings and valve train. Thread's in chat under '7.4 overheat...'

DougM

 

[cary]

Another problem with the consumer reports article was that by using vehicles that were constantly running, the oil never accumulated moisture and other contaminants that don't burn off during short trips on normal cars. These contaminants contribute to the oxidation and breakdown of oils. Basically, the NY taxi test was a test that was easy on oil. Also, keep in mind, some motors are harder on oil than others.