I guy on another forum made the statement that there was NO ZDDP in Shell Rotella. He said that the formula was changed last year. I know about the reduction two years ago, but has there been an additional reduction? Ted????

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

SM is the current gasoline engine oil classification.  If the oil is classified “SM” on the container, then being 15W-40 is expected to have at least ~1300 ppm zinc/phosphorus in it.  This is more than adequate for the older flat tappet engines.  If the oil has only a API Services “C*” classification on it and no “S*” classification to go along with it, then it’s diesel only and is not suitable for long term running in gasoline engines.  There are a number of diesel oils that have being dropped from the licensing process starting in the later part of 2009 and there are some others scheduled to be dropped at the end of this year so there are changes taking place in the current availability of diesel oils.  Just pay attention to the “S*” classification along with the rules that go with that and all will be good.

 

If there is both the “CJ” and “SM” classification on the oil, then depending upon the weight classification (viscosity) of the oil it may or may not have the necessary amounts of ZDDP for the older flat tappet engines.  This is where reading in detail the American Petroleum Institutes Service Bulletins will clarify exactly what is suppose to be in each oil grade.  But for us and in a very abbreviated format, any of the current SM rated oils with any viscosity numbers over 30 in the labeling (ie:10W-40, 20W-50) will have sufficient amounts of ZDDP for the Y engines.  30W or less will have the reduced ZDDP amounts by default on SM rated oils.

Lorena, Texas (South of Waco)

this is the oil I use

http://www.bradpennracing.com/Racing-Oil-Line.aspx

local dealer sells the 20/50 @ $4.50 x 12 = $54 a case

I agree!

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias