Backdraft book says use 20w50 oil

[Bxx1]

Not all motor oils from the same company are the same. Generally, I agree that Mobil 1 is not a top tier motor oil... But Mobil 0w-40 is one of their best oils. It has a VI index of 185. Most true synthetic oils have a VI above 165. Generally, the higher the VI the higher quality synthetic oil. I also like the fact that Mobil 1 0w-40 contains high amounts of Boron, which acts as a corrosion inhibitor and is considered an anti-wear additive (in addition to the Zinc and Phos.). I think it is a top quality oil, for my needs, in my 500 HP engine which gets used infrequently. I hate those cold starts but knowing it flows very well helps me overcome my apprehensions. Each to his own. Happy motoring.

[cbreez]

Originally Posted by Bxx1

It has a VI index of 185. Most true synthetic oils have a VI above 165. Generally, the higher the VI the higher quality synthetic oil.

Oh really, explain why??? Are you a chemist? What does VI mean to you? So more is better, eh?

[Bxx1]

I am only a chemist on the internet...

There is alot of info on the internet regarding motor oil, viscosity, etc. etc.
The link below could be a benefit in understanding some of the concepts of motor oil (especially regarding viscosity VI).
We all have our preferences for cars, motor oil, engines, etc. etc. I have found my preference for motor oil for my Cobra.

I hope readers find the link useful.

http://zddplus.labecon.com/TechBrief...0Viscosity.pdf

[eedeutsch]

My engine builder recommended 20w50 in summer and 10w40 in winter. He did
not specify any particular brand.