Attention: TDR Forum Junkies I am about to do my first LOF utilizing a synthetic at 23k. Considering PBE due to Cummins recommendation, in-store availability and consistency with DC manual viscosity recommendation (2004. 5 manual shows 5-W40 in synthetic, 15-W40 without specification as to synthetic/conventional oil, the 5-W40 of course carrying into lower anticipated temperature ranges). I have always used the Fleetguard Stratpore and will continue to do so. I think I read that in 05 or 06 the factory recommended change interval went way up, doubled perhaps from the 3750/7500 in the 2004. 5. I meet the criteria for the 3750 change interval based on some heavy towing and occasional high OAT operations.
My hope with the PBE is to change both the filter and oil at 7500 miles. I will probably do an oil analysis with the Delvac that's about to be drained, and future changes. Any thoughts on the real-world wisdom of such a plan, especially considering the factory-sponsored increases in subsequent years? I believe it is wasteful (both of natural resources, and my energy, which I guess is also a natural resource) to stick with the tried and true "every three thousand because that's what my Dad taught me and his cars lasted forever" theory on oil changes. While I want my truck to endure, I want to change oil only as necessary.
Also, out of curiosity, am I correct in understanding that Premium Blue Extreme is a true synthetic while Premium Blue is perhaps a blend or conventional oil? Both carry the Cummins blessing, but the Valvoline web site does not seem to use the term "synthetic" in its discussion of non-extereme Premium Blue.
My hope with the PBE is to change both the filter and oil at 7500 miles. I will probably do an oil analysis with the Delvac that's about to be drained, and future changes. Any thoughts on the real-world wisdom of such a plan, especially considering the factory-sponsored increases in subsequent years? I believe it is wasteful (both of natural resources, and my energy, which I guess is also a natural resource) to stick with the tried and true "every three thousand because that's what my Dad taught me and his cars lasted forever" theory on oil changes. While I want my truck to endure, I want to change oil only as necessary.
Also, out of curiosity, am I correct in understanding that Premium Blue Extreme is a true synthetic while Premium Blue is perhaps a blend or conventional oil? Both carry the Cummins blessing, but the Valvoline web site does not seem to use the term "synthetic" in its discussion of non-extereme Premium Blue.
