Hi Alex, I think you are right about Delvac 1 being a superior oil than Mobil 1. When I originally looked into Mobil 1 vs. Delvac 1, I called Mobil (800) 662-4525 and spoke with two different engineers on two occasions and asked them which oil they would recommend for my American Diesel -- Engine oil recommendation is CC or CF (New Classification). The answer I received was Mobil 1. What I was basically told, was that my engine would never operate in the range where I would realize the benefits of Delvac. Mobil 1 is widely available and significantly exceeded CC/CF requirements. I don't believe I mentioned that I was going to use the oil with a bypass filter. Do you think an engine that has an engine oil recommendation is CC or CF would benefit from the Delvac? Thanks, Al Pacific Trawler 37 "Pleasant Moment" Palm Coast, Florida

----- Original Message ----- From: "Dr. Al Miller" <almiller@n-jcenter.com> > > Do you think an engine that has an engine oil recommendation is CC or CF > would benefit from the Delvac? > Hi Al, If this response seems rude or harsh, I apologize. 1. Delvac 1 is superior to Mobil 1 for diesel engine service. So, yes, your engine would benefit from its use. 2. You, your children and probably your grandchildren won't live long enough to see the result of those benefits. 3. OTOH: Your wallet should benefit almost immediately. When I worked for a Mobil jobber several years ago Delvac 1 was approx. 25% less money than Mobil 1. My information is, admittedly, out of date but there are reasons to believe that the price difference still exists. 3a. You need to be aware that Mobil pressures their people mercilessly to push Mobil 1 (voice of experience). 4. Unless you are using the 15w50 version of Mobil 1 your engine will be happier with Delvac 1's higher viscosity. 0w30, 5w30, & 10w30 are IMHO too thin for your American Diesel. 5. If you were to go looking for Mobil 1 15w50 I think you'll probably find that Delvac 1 is just as easily available. BTW: Your best bet for finding either product will be with a Mobil Jobber/Distributor. Check the Yellow Pages under "Oil - Lubricating". 6. Finally, I'd like to reiterate something I've said before on this subject: I have yet to hear of a recreational trawler engine in which a synthetic oil makes economic sense. Please note that I'm not saying that they're bad products, just that you won't reap a net benefit from their use. IOW you'll be better off if you buy a nice premium mineral based oil like Mobil Delvac 1300 Super 15w40 and spend the money you save on a fuel polishing system, a DSC radio, upgraded SOLAS flares, or even beer. I could go on but I'm starting to get even more redundant than usual. Pragmatically yours, Alex