Api Sm/sj/sl/cf

[raunch]

Is the API rating listed in the post title OK for use in a 6.2? It's 10W-40. I was thinking of trying a synthetic for the winter, and Castrol Syntec was the only one other than Royal Purple (aka liquid gold) with a 'C' rating I could find so far.
Thanks.

[rogers]

There is some good information about API ratings here (http://www.aa1car.com/library/API_ratings.pdf). I think this chart is a little out of date but will give you good direction for the oil you are looking at.

[DmaxMaverick]

NO. None of the above. That's gasser oil. The "C" rating alone is not enough for late model automotive Diesel engines (1978 and later). The earliest rating should be CG or later for a 6.2L. CF is before CG. Probably fine in an old farm tractor, but using it in your 6.2L will be a gamble. Saving money is great, just be careful where you do it. Weigh the cost of an overhaul vs. money saved on surplus oil.

[raunch]

Thanks for the info.