Mobil 1 burns off easier than other oils?!?

[Hence]

I've been using Mobil 1 in my BMW since around 55,000 miles.

[JuiceMan]

I went through this same problem about a year ago with a 1993 Ford F-150 (302) the truck only had 27,000 miles on it and the original owner always used Valvoline in the truck and never had any problems. So I kept using Valvoline for about 2 changes (6,000 miles total) after I purchased the truck and it never smoked, leaked or used a drop of oil.

I then switched over to Mobil 1 synthetic. Drove the truck 1500miles and I want a quart low on oil still no smoking or leaking though. Added the quart drove some more and the truck used another quart in 1500 miles. I changed the oil using Mobil 1 again and the exact same thing happend two quarts gone in 3k miles still no leaks or smoking of any sort.

Switched back to Valvoline and never had any problems and no oil usage at all the truck now has over 80k miles and is no longer in my possesion

[zuffenhausen]

It's not that Mobil 1 burns easier than other oils (in fact, it doesn't burn well at all which is why some race engine builders avoid it) but that it gets to places that conventional oils don't! Many people have complained about putting Mobil 1 in an older engine and having it leak out of nearly every seal and gasket when there were previously no leaks. That's not really the oil's fault, though the only solution short of replacing all the seals and gaskets is to switch back to the conventional oil.

In your case, Brian, since you've been using Mobil 1 for a long time with no problems, the sudden change in oil consumption was caused by something changing in the engine. Since you don't see any leaks, it's going out the exhaust. Again, Mobil 1 doesn't burn well so you really won't see a lot of the traditional blue smoke, but it's still being pumped out the exhaust. It's possible that the head gasket has begun to let a little oil through, or that a ring has stuck.

One thing you could try is pulling the plugs and inspecting them. If it's a ring problem, it would only affect one cylinder and one plug should be more oily than the others.

Don't get too worked up about it as I doubt it's anything really serious. It will probably just remain an annoyance for a while. However, you should check your oil frequently for signs of coolant mixing. Once that starts happening, head gasket failure is imminent and at 126K miles, a head gasket replacement would not be unusual.

I've been a big fan of Mobil 1 for many years, but in some cases it's almost too good.

Regards,
zuff

[Doug Zielke]

Very interesting!

Somewhere on the web is a site where various oil brands were (independently) tested. I remember(?) Mobil 1 had one of the highest flash points of any oil, synthetic or dino. I think only Amsoil was better.

(Still waiting for a petro-chemist to join the board someday and "enlighten" us about oily stuff.)