I personally would not use an oil designed for diesel engines any more than I would use diesel fuel in a gas engine.

Al Newman wrote:

In a previous thread recently, "Don" referenced a comprehensive comparison of several popular motor oils. That post precipitated several posts on the subject that indicates that the motor oil subject shares the same traits as religion and politics. Several of the responses extoll the virtues of using the diesel blended Rotella oil in our vintage flat tappet motors. I personally have no experience with Rotella, but, at a seminar on oils a few years ago, it was pointed out that Rotella is blended with additives designed to carry off or minimize diesel combustion residue as opposed to dealing with the stop-and-go and higher rpm operation of gasoline engines. Because of these differing additives, it was not advisable to use the Rotella in gasoline engines. This info is several years old. Is there some change in Rotella to negate this advice?
Really confusing!!
Best
Al

"Believe nothing of what you hear and half of what you see"...

Last edited by jerseyjoe (1/13/2016 8:07 AM)

Rudi wrote:

 Here I changed that for ya!
READ THE LABEL...EXCELLENT FOR OLDER WORN OUT  GASOLINE ENGINES
.
 I have used 5 -50 synthetic in my 331 since the break in with dinosaur oil.

Rotella...Like Franks Hot Sauce...I put that s_ _t in Everything....

Rotella is very good oil in both the T5 conventional and T6 synthetic variants.  I ran the T5, and now run the T6 in my '06 F250 6.0 Diesel.  The spec oil for that engine is the 15W40 T5, but Ford later revised that spec to a 5W40 and the T6 fits that bill nicely.  The 6.0, like the 7.3 before it runs an HEUI injection system in which oil pressure is used to fire the injectors.  This system is very susceptible to a phenomenon known as "stiction", in which deposits build up in the injectors and cause the spool valves responsible for oil flow from operating efficiently, sometimes getting stuck and causing poor running.  The synthetic oil helps keep this from happening due to its better thermal handling abilities and increased lubricity. 

I've seen a lot of OA on the T6 that shows that it is still going strong at 10,000 miles and beyond even in a hard working Diesel.

Personally I also noticed that when I first got my truck and started servicing it I was running the NAPA brand 15W40 Diesel oil, but I noticed that right around 5k, when it was due for an oil change the engine noise started to sound different.  I could literally tell the engine need an oil change by ear.  I noticed NAPA also carried the Rotella that Ford/IH recommend for the engine, so one oil change I decided to try it.  No more noise change as the oil change approached.  I'm spending a bit more on the Rotella than I was on the NAPA, but I operate on the philosophy that oil is cheap and engines are expensive.  Or in the case of the 6.0, injectors are expensive at $1,500 a set (more like $2,000 a set for the modified ones I run).