Quote Originally Posted by tuazon7 View Post
dvldoc, comparing again RP 15W-40 and Mobil 1 TDT with Motul Specific CRDI Diesel, are they on the same league? Almost on the same price range, 450 to 600...TIA.
Both those oils are good, but unless your running these at least 15000km your really wasting your money, A good group III oil will be perfectly fine especially if your only doing 10000km to 12000km oil changes, There is nothing that shows Group III cannot last just as long as Group IV true synthetics like Motul, Mobil and Royal purple.






Here is a interesting oil study done by the state of Californa with royal purple

http://www.realtruck.com/shared/pdf/...ple_report.pdf