Diesel Problem


LawnSite Member
What kind of oil do you use in your Diesel Mowers? The book for mine(15 years old) said to use SAE 30, but don't most Diesels run on 15-W40 since it is a heavier duty Diesel oil? Has anyone tried just Valvoline SAE 30 in thier Diesel engine?


LawnSite Gold Member
If you run 30w oil be sure it is diesel aprroved, if not it wont have the correct additive package and cause failure.Back in the 80's detroit diesel used 30 weight oil and cummins used 15w40. The fleet I worked for switched all of our engines to shell rotella 15w-40. It preformed well, it is easy to find and the price is very good compared to some other oils. We never had any engine problems switching the weights of the oils


LawnSite Member
Cheyenne, WY
Shell rotella 15w40 is all I would ever use in a diesel. I've had four different powerstrokes anywhere from 235,000 up to 285,000 miles and never had an engine problem.


LawnSite Silver Member
S.E. Michigan
If it says SAE30, then use it. Older Ford Diesel tractors use 10w30 oil, as long as it meets "CD" classification. Remember, it doesn't matter how old your machine is, SAE30 today is far superior to SAE30 10 or 15 years ago. If it was good enough back then, it's good enough today.


LawnSite Bronze Member
Shreveport, La.
i vote rotella , thats all i use in my diesel

Albemarle Lawn

LawnSite Bronze Member
Saw it for sale yesterday at tractor supply in gallon jugs.

Whatever oil you put in a diesel, it has to have the CD/CH rating.

The "C" stands for Compression Ignition, the "S" in an SH rating stands for Spark ignition.

The viscosity is more a function of what temperatures you have for overnight lows...if you are in a really cold zone, you may want to use Rotella 5w-40 synthetic diesel oil.


Mr DanO

LawnSite Member
forest lake mn
Rotella? Why not just run olive oil? Chevron delo 400 15/40 multi grade is the only oil I have used in my semi's for over 20 yrs. Try walmart they sell Chevron,mobil and that other so called oil rotela