Wildbill: You are still not providing any information. Just a bunch of heresay. Do you think that Swift, Schneider, CRT and other big carriers are having engine troubles and coking?? Those carriers do NOT use synthetic oils.Being as most RV'rs are using dino oil where are the posts that they have had coking? Modern engine oils have super additive packages and other than cold weather flow your synthetic has no value for an RV'r. BTW: Trucking Companies do use synthetic oils in diffs and manual transmissions but hardly ever in diesel engines.
Moisheh
2008 Dynasty 42 ft.
2005 Bounder 34M DP, small fleet consisting of 4 propane forklifts, 3 class 5 Diesel trucks, 1 pickup, 2 SUV's, 2 autos and a case tractor/backhoe!!!!!