Cat C-7 diesel oil viscosity
I have a 2004 Cat C-7 in a 36' Meridian which I have been using Rotella 15W-40 oil in it since new 68,000 miles back. Seems I remember reading somewhere the thought was that 10W-30 was better for the...
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Fire Up: I think you meant 10/30 or 15/40. delo does not make a 10/40 The reason for the 10/30 recommendation ( according to jauston and others) is that the injectors use engine oil to operate. Apparently 10/30 will help with that system. As for finding someone with a C7 that has 200,000 miles without HEUI problems. GOOD LUCK. The C7 is not a good powerplant. The HEUI system is horrible. There are examples of people with less than 40,000 miles who have pump problems and the cost is many thousands of $$$. The problem is that very few entry level MGH's produced from 05 to 07 have anything other than a C7! Someone on IRV posted the latest oil requirements for cat engines. It states that 10/30 is preferred but 15/40 can be used. I called cat about 3 months ago and the tech said either is OK. I understand why some think the lighter oil will help with longer injector life but I am of the opinion that regardless of the oil used failure is inevitable. There is a small bonus using 10/30. Delo claims a 3.6% fuel mileage increase.
Moisheh
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Moisheh
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