path1 wrote:
We spent time with a retired Cummins engineer. Good guy with tons of good stories. His theory ..... OEMS's stretch maintenance schedules for as long as they can for sales reasons. (And bean counters always win, but really have no idea about the mechanics of a product and only think about cost of ownership compared to other OEM's) And consumers have no idea how long something has sat around or what conditions fluids or filters were stored in.
His advice...follow maintenance schedule but back up 10 percent. Example...if something is due at 10,000 miles to it at 9,000 (10,000 minus 10 percent)
As one who has also worked for Cummins and other vehicle manufacturers, I can honestly say that I disagree with this 110%.
There are many variables that go into when you should change your oil including, but not limited to fuel consumption, contamination holding capacity of the oil pan, the contamination holing capacity of the filter, contamination holding ability of the oil, and the load/duty cycle of the engine. A quick oil analysis will tell you that a Cummins 6.7L with and SCR will easily go up to 15k intervals which is what is recommended.
In fact, this is what Cummins has to say about oil change intervals on the 6.7L per my Cummins Quickserve.
As far as Cummins endorsing Power Service. Generally when a manufacturer endorses a specific product it is because they have some sort of monetary agreement with the manufactures of that product.
Take the case of Cummins endorsing and recommending Valvoline. Cummins gets a better deal on the factory fill oil and other lubricants used in the engine building process that they purchase from Valvoline by publicly recommending and endorsing them. However, if you go to Cummins Quickserve, then you will see that every other oil that meet Cummins standards can be used as alternatives.
This is only a screen print of a few of the alternative oils. Trust me, the list is long and just about every major oil brand is on there.
