PoorMansCat

When my buddy bought his CTD, the dealership told him it had to be changed every 3000 just like a gasser. Our new Honda Civic has a longer change interval than that!!!!. I brought him an oil sample bottle and we sent it off to the lab, come to find out, the dealership was putting automotive engine oil in it. He's now putting Cat DEO in it at every 6000 miles...(and he quit doing business with the dealership!) We have some pretty extreme heat here in the summer, according to the oil samples we've done since, we could have pushed the CAT oil alot futher, but... He and I have both decided that 6000 is a good even number that still leaves a little room for error and getting good service life out of the oil.

gsbrockman

Casper gets 5W40 Rotella-T, an LF16035, and a FS19579 every 8k miles. Oil & filters are cheap; engines are expensive.

Greg

Hounddog

3k oil changes is a by gone era.Engines burn cleaner and oils are much improved.After reading www.bobistheoilguy.com even the cheaper oils have decent additive packages that go a lot longer then 3k these days.Lots of BORING reading but do a search and read about oils until your blue.

Rpainter

I got close to 30,000 on my oil .change bypass and full flow every 10,000 analysis said good oil keep running.

fbx22

I agree 100%. These old 3000 mile oil change cliches are from the carbeurator days. All these lube places and dealers that still say 3000 miles irritate me to no end! Yep cars operate cleaner and oils are better than 20 years ago. Ive been changing at about 5000 mile intervals for several years now on any vehicle Ive owned. IMO the 3000 mile change is complete garbage

tmgxray

my 04's oil is clear almost til 10k miles, so I change mine at 10k intervals with rotella 15w40 and fleetguard filter. Some people might think thats crazy, but the 305 horse engine's oil looks good up till 10k miles.

moterhead

Remember, a service department is in the business of selling, guess what? SERVICE! I think that since DC is providing the warranty and Cummins built the engine, they should know what is necessary for a long and useful life. Much more so than someone who has a vested interest in selling you over twice the service your truck actually needs (3000 mile changes vs 7500). If the cost of the excessive service isn't a consideration, do it to conserve natural resources and reduce the amount of used motor oil to be disposed of.

Hounddog

I will say that when when I sold service if you pushed 3k oil changes folks seemed to manage to get it done between 4k and 8k. You cannot image how many ignore the sticker in left corner of the windshield with every excuse under the sun.If they REALLY stuck to 5k changes everthing would be fine.I had lots come in wanting a full 15k service and THATS when the oil got changed.

Farmer Davis

Most mechanics I know recommend 5-7K with conventional oil. Longer on synthetics. I have also heard stories of dealers using cheap automotive oil. Seems like your safer changing your own oil, if you can.

fbx22

yeah no kidding. I actually known people that might get their oil changed every 2 years or so, and some not at all. They think an oil change means dump another quart in there because when they check the dipstick the oil is low. Probably because its burned up a quart from being in there so long I also worked for a company that thought the only service ever needed was oil changes every 7000 miles with their synthetic oil from some mobile oil service. They never changed differentials, trans fluids, air filters, or anything else except the oil

TonyB

I hate to admit it, but that was me 10 years ago! Boy have I learned! Towing has really opened my eyes. I NEVER want to have a failure on the road.

Tony

CD in NM

I'm using the Valvoline 15w40 Blue - oil and Stratapore Filter @ 5K intervals.
Amsoil Bypass filter @ 10K - every other oil change.
7-nm canister fuel filter 10K - every other oil change.
2-nm GDP fuel filter 10K - every other oil change opposite canister.
Axles - Amsoil 75w140 - 1st change @ 5K - then 15K intervals.
Trans - Amsoil ATF - 1st change @ 5K - then 30K intervals.
T-case - Amsoil ATF - 1st change @ 5K - then 30K intervals.
Lube the few zircs we have every oil change. Clean my Amsoil nano air filter at every oil change. Tire rotation every 10K.

I tow heavy about 65% of the time, live in a hot and dirty climate. My previous trucks (gassers) had virtually NO problems with anything for 300K+ miles on them other than normal wear parts using these change intervals. I'd rather put my money in this stuff. When it is all calculated out over time, this saves money and down time is all but non-existant. I recycle all my oil into my generator, tractor, Bobcat, chain saw, lawn mowers, etc and after they have had enough use out of it I burn it in my garage heater.

CD

edited ATF timeframe - thanks Hounddog!

Danderson

The oil on my '99 was clear on the dipstick@5,000 oil change intervals. However,upon draining it,it was black as coal. This '07's oil is black in about ten minutes after change.

Hounddog

CD in NM.You could go a lot further on the Amsoil ATF in the trans.At least to 30k.I'd do the auto and transfer case the same intervals.

CD in NM

Hey Hounddog.

Typo error on my part, I meant to have it at the same interval as the transfer case. I'll edit it to correct it. Thanks for pointing that out, someone came to the door and I just hit the post and did not catch it. Mind somewhere else.

CD