Synthetic ??

[30coupe]

I also found this:

http://www.trustmymechanic.com/motor-oil-bible.pdf

As near as I can determine, this guy has no connection to AMSOIL. It is part of this website: http://www.trustmymechanic.com/motoroil.html

I did a google search for best motor oil and this is one of the sites that came up. I am not trying to justify Amsoil, but your posts got me wondering about it. The Motor Oil Bible is pretty long and technical, but toward the end it has comparisons of many motor oils. Amsoil ranked at or near the top for each weight of oil, so I guess I will continue to use it. With the extended drain interval, it is actually cheaper than even dino oil. The bible guy also explains the API license thing. Amsoil is not the only one that doesn't have the API license, apparently several premium oils do not carry it, for much the same reason as Amsoil.

The bottom line is, synthetics are generally better than dino oil, but it pays to do your research. I did, so I am sticking with Amsoil.

 

[Totalled]

Castrol GTX...

 

[protomind]

Hmm I am running and have been running Mobil 1 extended performance 5w 30 in another car, and will be putting it inside of my v6 4.0 86k explorer. What you guys think?

 

[MAKG]

Spec is 10W-30. It will work just fine.

5W-30 may be a little rough on the engine during cold starts, as it's a little thin. But not all that significantly.

5W-30 and 10W-30 are identical for a warm engine.

 

[almostclueless]

Castrol GTX...

Preach it.....all I will use in roller lifter engines.