Oil change interval

[Una]

How long are you guys going between oil changes? Standard 3,000? I see that the oil gets pitch black pretty much instantly on a diesel motor. I'm running Royal Purple synthetic and a high quality large oil filter, but I don't want to push it, I'm ok with spending the money to do it from time to time if it will keep the engine healthier. I know on my gas motors, I go 5,000 between changes and the oil comes out a nice brown color that light can still pass through while it's draining out of the engine. I doubt my 1,000 mile oil could do that from this diesel motor.. heh..

[82vdub]

In my Rabbit, I change the oil/filter once a year (irregardless of miles driven), in the spring when I start driving the car for the year. I do change the add on filters every 3-4k though. Here's why:

viewtopic.php?f=8&t=7712

[coke]

What royal purple synthetic oil are you using? The stuff I sell at one of the auto parts chain stores is not rated for a diesel engine. I run Rotella T6 Synthetic 5w40 in my car, and its about 20 bucks a gallon, which in my experience is a lot less than the royal purple stuff we sell.

[air-cooled or diesel]

dont worry about black color, 5k-7k sounds about right as a ballpark guess for synthetic, some oils can go some more, make sure your stuff at least works properly in a D. diesels (D) dont have the contaminates that a gas makes.
if you want there are oil flushouts aval.

[Una]

What royal purple synthetic oil are you using? The stuff I sell at one of the auto parts chain stores is not rated for a diesel engine. I run Rotella T6 Synthetic 5w40 in my car, and its about 20 bucks a gallon, which in my experience is a lot less than the royal purple stuff we sell.

I got it at O'Reily's auto parts for $36 a gallon. This car saves me enough on fuel costs, I don't mind spending a bit more on the best oil I can get. Here are two pictures of the bottle:

[DanHoug]

every 5k miles with dino diesel oil, not synthetic. but i drive 500 miles a week so it adds up fast. i have essentially insignificant oil consumption on this 350k mile motor with a re-ring at 250k. and yeah, it's black after the first day.

-dan

[Una]

Yeah, I put 650 a week on this thing, which is why I was wondering if I could push the change interval out to 5k or not. Sounds like I'll be just fine. I have no idea what kind of mileage is on my motor, thanks to a dead odometer when I got the car, and a possibility that it's got a different motor swapped in.

[JRM]

5k on dyno 15w40 anyting less than that is overkill, the block will ridge around 400k anyway. i change my dodge cummins every 10k.

[surfcam]

Most truckers are using Shell or Chevron oils. They are taking periodic oil samples for analyses and know which oils last longer before breaking down.

[82vdub]

Diesels have shortened engine life if the oil isn't kept clean. I'll take exception to these engines forming a ridge at 400k miles, if the oil is kept clean. When the head was last off my car at about 300k, there were still factory hone marks in the cylinder walls. My car has had the additional oil filter on the car since it had about 5k miles on it. According to fatmobile, you get about 125k on the front intermediate shaft bearing before it starts to flake apart. Then mine should have been replaced 2 or 3x now, but everything inside the block has never been apart. I attribute this to the external filters that have been installed on the car. Then again, maybe I just got lucky.

[coke]

Keep in mine just because the oil is black doesn't mean its bad. My oil turns black the moment I put it in the engine. I change every 3-4k. Use Mann filters.

[Una]

This thing had a Mann filter on it when I got it. It was half the size of the K&N I replaced it with

[82vdub]

Coke, I agree with you partially. It's black for a reason. Exactly what's in the oil to turn it black (soot??) I don't know, but it sure isn't exactly "clean" oil.

[air-cooled or diesel]

well i'll enlighten you all. the reason diesel motor oil turns so dark is :ta da carbon, which i beg to differ will not lessen your engine life. quite the contrary it acts as a lubricant its self by soaking oil up
so there you have it.
change the syn oil at over 5k, i go 6mo and change.
main thing of a diesel is the air filter then the fuel filter (as the parts are so delicate) and your oil comes not too far Last.
carbon fellas from blow by, thats it

[vixentd]

The time to change oil is based on how your car is driven. If it is a daily driver and driven short distances less than 10-15 miles, it will not come up to temperature to burn off any moisture in the oil. The moisture combines with the oil to form a caustic substance that is very wearing on motors. Change your oil every 5,000 miles or 6 months. If you are driving for more than 25 mins a day at a time, you can extend your oil change intervals.