Delvac 1 and gas engines

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Staff member
May 27, 2002
Guelph, Ontario
I know this topic has come up before but this is a different question about it. I know a lot of
people here have used Delvac 1 in gasoline engines, but someone on my car club's mailing
list raised a pretty good point. He said that because it's a diesel oil, it may contain less
antifoaming agents, since diesels turn such low rpms and don't need as much of them. So
if someone was to run Delvac 1 in a high revving gas motor, would they run into problems?
My Volkswagen TDI diesel has a redline of 4700 RPM and is regularly revved to 4500 RPM with no problems from the Delvac-1. I don't know what you consider high RPM but my motorcycle has a redline of 11,500 RPM and it sees that regularly also. I have used Delvac-1 in it and again have had absolutely no problems.

I don't believe foaming is a issue with this oil even if it does have less foaming agents which I don't know that it does. This is a pretty impressive product.
The API foam test is run on a Navistar diesel where the circulation is high and there is a history of engine failure from foaming. This engine presurizes the oil to 3,000 psi and circulates the entire 13.3 lt capacity every 8.8 seconds.
The Navistar Power Stroke diesel used in Ford pickups uses engine oil as the hydraulic oil in their fuel injection system. Can't have foaming, obviously, and the well known Mobil, Shell, Chevron (and other brands) diesel lubes work fine in this regard.

Delvac 1 defintely has the anti-foaming agents as mentioned above.

The Navistart T444E and Ford Powerstroke derivative of the T444E both use Cat. designed fuel injetion system called HEUI. The injectors are hydraulically actuated using motor oil. There is a regular oil pump and a high pressure oil pump for the top end of the motor. The bottem end oil pressure is your typical automotive pressure. The top end pressure is indeed in the 3000PSI range mentioned above.

Mobil 1 can't hack it in these motors but Delvac 1 works like a charm.
I'm currently running Delovac 1 in my 98,125k mile, Ford F-150 V-6 gas engine. Has around 6k on it right now. Of the 6k,3k, was a very hard run from Texas to Idaho and back. No problems to report.

I don't plan on using it any more, the cost is very high, locally $27/gallon.

As soon as my Schaeffers oil arrives out goes the Delovac in goes the Schaeffers #700 15w-40.
I'll 2nd what FowVay said. I have used Delvac 1 in my Honda VFR for many years and it's redline is 11,500 rpm. It has better specs than Mobil's absurdly overpriced motorcycle oil.
Thanks for the info! If it works in an 11,000+ rpm motorcycle engine, it'll work in anything!
First I'd like to address Patman's post re: Delvac use in a gasoline owner's manual says: "oils labelled as diesel engine oils CE/CH or higher may also be used as a substitute for SE/SH" (owner's manual from 1994).

Secondly, I don't own and have never owned a motorcycle but, don't bikes have a "wet clutch" system that requires "motorcylce" oils for this reason?
Does anyone have specs comparing the Mobil for bikes to the Delvac? If it has the JASO-MA stamp then it is suppose to be ok for a wet clutch.

Delvac 1, CI-4/SJ, 5w-40, Flash Point of 439F
Pour point of -49F
VI of approx 160

MX4T, CF/SH, 10w-40, Flash Point of 487F
Pour point of -65F
VI of 164

M1-VTwin, CF/SH, 20w-50, Flash Point of 518F
Pour Point of -60F
VI of 154

My educated guess would be that the motorcycle oils contain more ester in the basestock blend. The additive chemistry has also been optimized for a high temp, gas engine application as opposed to a diesel.
Other than an aricraft gas turbine, I can't think of a higher temperature operating engine than the diesels with their > 16:1 compression ratios and highly pressurized oils.

Oils like Delvac 1 are definately multi-vehicle, fleet oils.

Originally posted by Chris:
Does anyone have specs comparing the Mobil for bikes to the Delvac? If it has the JASO-MA stamp then it is suppose to be ok for a wet clutch.

Delvac 1 passes the JAY-MA test in my bike.

The rumor was that the API Energy Conserving II category oils "might" cause clutch slip in some bikes. Delvac 1 is not an Energy Conserving II oil. I never had a problem with clutch slip using the ECII oils anyway.
Jay, what specs do you have for the Delvac that are better than the Mobil 1 for bikes?

Diesel oils are formulated to minimize polishing wear with high soot levels, by keeping the soot dispersed in the oil. They are also formulated to neutralize sulphuric acid and prevent high temp piston deposits. In order to accomplish this, they generally contain very high levels of alkaline detergent/dispersant additives.

With gas engines you are most concerned with nitration and preventing high temp oxidation and thickening. You also want to minimize the amount of sulphated ash to prevent spark plug deposits.

In other words the additive chemistry of Delvac 1 and the Mobil 1, 10w-40/20w-50 oils is going to be somewhat different. They may even use a different type of ZDDP compound, depending on the application. Diesel oils generally work pretty well in bikes, as they have high additive treat levels and they aren't friction modified. But this doesn't mean they have been optimized for motorcycle use ....

Originally posted by Chris:
Jay, what specs do you have for the Delvac that are better than the Mobil 1 for bikes?

I have different specs for Delvac 1 than TooSlick posted:
PP -65degF
FP 464degF
Delvac 1's VI will be higher than the MX4T and the Delvac 1 has better cold temperature cranking and pumping specs than MX4T, ovbiously, and at the same time it's quite a bit thicker at 100 deg C. And the best spec of all is Delvac 1 @ 5.25/qt vs 8+ for the MX4T.

I have no argument that the MX4T may be better suited to motorcycles than Delvac 1. I dispute that it's $3.00/qt better for bikes than the Delvac 1.

The specs you posted are for the previous, "CH-4/SJ" formulation of Delvac 1. Both the flash and pour points have changed with the reformulated "CI-4" stuff that is currently on the shelves ....The VI of the old formulation was 167 as I recall, but the newer product doesn't do as well in this area.

Delvac 1, CI-4

Viscosity @ 40C, 102 Cst
Viscosity @ 100C, 14.8 Cst
VI, ?

This degradation of high/low temp properties has led some folks to question whether this formulation contains some Group III basestock. However, I have been assured this isn't the case. The updated spec for Delvac 1 is located on Mobils Industrial Lubricants page of their website.
Thanks TooSlick. I have not kept up with the changes in Delvac 1. I just visited their website and saw that the FP is 446F but I still see the PP as -65F. I didn't see any date on the product data sheet.
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