Rotella is a Diesel engine oil......

[Gerry]

Charles,
Thanks for the advice.

[steved]

As far as an over the counter product, I'd recommend Chevron DELO 400 in the 15-40 grade. This is likely the best oil that is available at Wal-Mart.

You had better qualify that with "was the best"...the newer Delo 400 LE is no where near what the older CI-4 offering was. You will be hard pressed to find OTC Delo 400, not the LE variety.

Coming from the diesel boards, and running used oil analysis myself, Rotella 15w40 seems to be on top of the pack in the OTC oils...with Amsoil and Schaffers being the better synthetics. I typically run 10k oil changes in my Cummins with UOAs stating the fill of Rotella is good for continued service.

And FWIW, the only reason a diesel oil shouldn't be used in a gasser is because the extra zinc found in diesel oils will fowl catalytic converters...zinc is part of the anti-wear package found in oils. The only other reason is it costs you mileage...thicker oil is harder to pump.

So unless you run a cat on your M37 or are hoping to get 40+mpg out of it, 15w40 would be the better choice. Plus, diesel-rated oils are better at controlling soot and excess fuel than gas-rated oils, which I'm sure we would see in some of these loose tolerance 6-cylinder engines.

When the time comes, I will be running Rotella in my truck.

[MSeriesRebuild]

As far as an over the counter product, I'd recommend Chevron DELO 400 in the 15-40 grade. This is likely the best oil that is available at Wal-Mart.

You had better qualify that with "was the best"...the newer Delo 400 LE is no where near what the older CI-4 offering was. You will be hard pressed to find OTC Delo 400, not the LE variety.

Coming from the diesel boards, and running used oil analysis myself, Rotella 15w40 seems to be on top of the pack in the OTC oils...with Amsoil and Schaffers being the better synthetics. I typically run 10k oil changes in my Cummins with UOAs stating the fill of Rotella is good for continued service.

And FWIW, the only reason a diesel oil shouldn't be used in a gasser is because the extra zinc found in diesel oils will fowl catalytic converters...zinc is part of the anti-wear package found in oils. The only other reason is it costs you mileage...thicker oil is harder to pump.

So unless you run a cat on your M37 or are hoping to get 40+mpg out of it, 15w40 would be the better choice. Plus, diesel-rated oils are better at controlling soot and excess fuel than gas-rated oils, which I'm sure we would see in some of these loose tolerance 6-cylinder engines.

When the time comes, I will be running Rotella in my truck.

I'm really not sure of the specs with DELO 400 at the present since we haven't run it in a few years now. Our Cummins repower trucks get Rotella T 15-40 when we install them here. I run Royal Purple 15-40 in my own Cummins engines. The reason we don't put that in the new engines is because they recommend not running it before the engine has 10,000 miles on it so it is properly broken in. Our rebuilt 230's also get Rotella T 15-40.