When to change oil

4x4ord wrote:

Grit dog wrote:

p220sigman wrote:

FishOnOne wrote:

Grit dog wrote:
This thread gets funnier by the day!

It really does... :B

And the irony is that the vast majority of people change the oil (or more likely have it changed) when the vehicle tells them it is time.

Except 4x and that other guy who posted he goes double. I don't do UOA's. Don't care. I change on time or a little early or whatever my spidey sense says. Since the oil I'm "wasting" by not extending due to UOA or the 4x4ord theory costs me maybe 5 hundredths of one percent of my annual income. Or 0.0005/100.


Serious question. If Ram says 15k and Frod says 10k miles OCI, is the additional wear on Ford oil really 33% more, IE are Fords really 33% harder on the oil?

My question as well. Although unlikely, one possibility is that the Powerstroke runs at hotter temperatures which could conceivably cause oil to deteriorate quicker. Another possibility that I think might be more likely is that Ford comes up with their oil change interval based on automotive standards whereas Cummins comes up with Rams oil change intervals based on industrial standards. Industrial powered equipment often has 600 hr change intervals. These engines are used at about 80 to 110 % rated load all day long and often run in extremely dusty conditions. My spider sense tells me that North America car manufacturers make a lot of money off the service department and if they were to recommend extended oil change intervals they would loose out on a lot of money.

I hate it when I go into a car dealer and they have big signs in the service department saying that they recommend changing oil ever 5,000 miles, regardless of what the manufacturer says. That proves to me that your theory them putting profit ahead of need is correct.