My preference is for 10W-30 Mobil 1 synthetic oil. The cold crank test for W grading show that the two grades are only a few undred cP apart. I have a good friend of mine, Bob Pache, who is retired from Mobil oil, and he was one of the chemists who formulated the Mobil 1 synthetic oil. He retired at 62 and still does some PR work for them. He is currently on the payroll of the Penske racing team and forumlates the oil for their race cars. If you have any more oil questions regarding Mobil 1, you can go to my forum and I have a Mobil 1 section for these types of questions. He'll be happy to answer you. He doesn't always get back right away, because he's traveling with the Penske Team.

Here's a link to the SAE vis chart that Bob sent me.
http://www.fatherlarryscorvetteshop....?threadid=1563

http://www.fatherlarryscorvetteshop....?threadid=1519 pic

 

I prefer 5w20 synthetic for mine as Ford recommends........

Dan

 

It seems kind of odd that on the 99-00 L 5W30 was recommended and from the 01 L up 5W20. Nothing was changed in the motors other that a redesigned intake manifold. It has to be all about gas mileage numbers.

I've always used Mobil1 5W30. I just bought the Advanced Formula which cost about a dollar more a quart. I don't know if it gives any more protection for 3,000 mile changes but it says 15,000 mile protection on the bottle. Who knows.

 

I run Mobil 1 5w30. Isn't 10w30 a bit thick for a modern gas engine?

 

Yep, you got it.

That's why I run Mobil 1 5W30 in my 2004 L. It appears to have quieted the engine down significantly over the 5W20, which I always knew was too thin of an oil for our engines.

Not that running Motorcraft or full synthetic 5W20 oil is bad. I just feel for the climate in my area, I can safely go with either 5W30 or 10W30 full sythetic.

Steve

 

Mobil 1 is a great oil, but Amsoil generally beats it in tests and specifications. Again, any synthetic is so far superior to a petroleum oil that from a wear perspective, you probably wouldn't notice a difference between brands of synthetics.

 

I just changed the oil in my L to Mobil 1 5-20w. This is the first time I saw in for sale in my local auto parts store, as far as I know Mobil 1 is just now becoming availble in 5-20w. Or perhaps it just now becoming available in the NW.

Charles

 

The 0W20 is equivalent to the 5W20.

The stuff your seeing is the new 5,000, 10,000, and 15,000 mile service Mobil 1 synthetic oil (we have it here in CA). They don't market it for some reason in the regular Mobil 1 as 5W20 anymore (weird).

No big deal, it's all good stuff. Just change it on a regular basis and use a good filter.

Steve