Well? Myself, I do it every 10K now. I used to change every 3K, but I don't really think it makes that much difference. And at $60 per lube job, it saves me about $135 or so every 10K change.

 

I run RP in mine so every 6k miles I change the filter and top it off. I totaly change the oil every 3rd filter change which is around 18k. My Blazer even though its not a Cummins I run 15k and just change all 3 filters and top it off. Yes its filtered 3 times, it may be overkill but thats what happens when you have extra parts laying around the shop. lol It doesnt get full oil changes though, just filters and refill the oil.

 

I do mine every 6 months, works out to 3k - 5k.

 

Wow you need to get out more, I do that much driving every 2 weeks. How is your truck ever going to get broke in at that rate.

 

Tho ol' Benz gets a lot more miles than the Dodge.

 

i was talking to a guy with a 95 cummins truck and it has 550,000 on it and he hasnt run an air filter (open turbo) or changed the oil in it in 4 years. daily driver 5,000 miles a month, no 2nd gear or overdrive in tranny. true story.

 

Yea, I change mine every 5,000 with a factory Cummins Fleetguard filter. I find it's not worth dropping it at only 3,000 miles because at that point the oil is not even remotely close to being black (like condition of most diesel engine oil). At 5,000 it's like a medium brown and I can see that as the engine is just getting broken in.

 

I normally use Amsoil syn change every 15-20 thousand

 

i never change oil! its a waste of money! just top it off and change the filter! 180k and still goin strong!

 

I change mine every 5000 or 1 year.

 

Amsoil. Used to run 5-10k, change filter and top off and run another 5-10k.
Now I just do an oil analysis. Got 12,500 on current rotation. I changed the filter after a year out of guilt.

 

When the oil light comes on, thats what its there for isnt it ? ?

 

Every 4-5k...

 

i change mine every 5000 i find every 5000 the oil is still clean as if i just put it in and doesnt move from when i filled it last

 

That involve sending it to a lab, or something else? I have thought about sending some off to the lab to find the ideal point at which to change. I think the every 3K miles mantra is pure BS from the quick lube lobby anymore. Of course, I do use good oil but I don't do synthetic. My mix is Rotella 15/40 (dino oil) and 1 gallon of Lucas every time.