C9 oil

[Ggrvusa]

My local mechanic uses 15/40 weight on my 2006 C9. I live in Ft. Lauderdale, FL. Cat says that I should be using 10/30 with the outside temp under 104 degrees. It never gets that hot down here. My mechanic insists that 10/40 is the way to go. Also we spend summers in CO at altitude, and it drops into the 40's at night. any thoughts?
Gary Goldman
2007 Revolution 40E

[1ciderdog]

I've read the same about the C-7. Rarely does it break 100 in the ares where I live but I do take trips where the temperature does exceed 104 degrees. So just my opinion - I'm sticking with the 15/40.

[Tha_Rooster]

Rotella 15/40 for engine and gen. for me and may other c-9 owners.

[jauguston]

There are two places to get the correct answer to what oil Cat recommends for your engine. This Forum is NOT one of the two.

First the Engine operation and maintainance manual has the information as well as the Cat web site.

The second and best is to call the National Cat RV Engine Tech Support Center.

I just went through this procedure after reading disagreeing ideas on these Forums. The Cat Tech Support guy said 10-30 oil meeting Cat specs is the recommended oil when the operating temperatures are generally between 0 degrees and 100 degrees. He also said the oil change interval that is usually said to be 11,000 miles or one year is not actually correct. Cat recommends oil change when 1100 gallons of fuel have been burned or one year. That means if you get 7 miles per gallon and that would not be uncommon the interval should be 7700 miles. He also said that Cat does not extend the change interval for synthetic oil.

These recommendations are for C-7 C-9 3126 and a couple of others.

Jim