Engine/Transmission (1994 - 1998) Oil Ratings

[fire8033]

Just looking to understand oil better and the different ratings. Does anyone have some information on the different ratings and what they mean? Also wondering if I can switch my regular oil to syn. without causing problems??? The truck has 186,000 miles on it.



Thanks in advance, this site has been very informational and well worth the membership fee.

 

[Texas Diesel]

You will get widly varied opinions of this, probably an oil war too :-{}



My simple suggestion is this, all the 1,000,000 trucks have used dino oil and OEM filters. Can you improve on that? If a syn oil makes 1,000,000 miles then they will have proven themselves to be as good as good ole dino oil in the Cummins application. This statement will start :-{}



A synthetic oil engine would need to make 3,000,000 miles before proves it's superior to dino oil (in the Cummins application)



I run synthetics (Royal Purple) everywhere else in the truck. I run RP syn motor oil in the engines of my BMW motorcycle(s) because the bike engine is a high stress affair.



The bottom line, IMO, is that the Cummins is so well built and under utilized, spend your $$ somewhere else.



You can switch to syn at any time, just change the filter at the regular first interval.



There is a web BBS just for oil questions, Bob the oil guy is the name. I will look for the url.





http://www.nordicgroup.us/oil.htm#Problems with Coffee



http://theoildrop.server101.com/cgi/ultimatebb.cgi



Those two links should keep you reading for hours.

 

[Johnstra]

I don't disagree with Texas Diesel that a well maintained Cummins will live a very long and happy life on dino, but I still choose to run syn in mine just for the added protection. I switched over at 160000 miles w/ no problems.

-john