I am rolling up on 18k on my 05 and am wondering when to switch to synthetic oil in the moter?? I am hearing everything from 10 to 50k. I dont tow very often and when I do it's only about 2000lbs. I try not to rally to often, but I don't baby it much either. Thanks in advance

 

I switched at 5k miles.

Rick

 

IMHO I would change to synthetic when the motor is broke in. That may be 15,000 if you pull heavy all the time or 30,000 if you do some pulling. My truck does run better after pulling something heavy. Every time I pull the better it runs. I am going to change at my next sevice interval. 32,000 miles.

 

I put syn in at 22k - would have done it sooner but I was paranoid, scared of hurting my precious CTD Not really - I couldn't afford it any sooner and it was cold outside! Picked up almost 1 mpg. Engine at 36k started getting over 18mpg the way I drive it. Got 38k on her now & she's smokin' like a leaf fire... Wait, that's the Banks kit...


I'm using Rotella T full syn - way cheaper than Mobile 1 ($14/gal at Wal-Mart) - then put the 3 gal of used oil back in your tank and save $9!!! Die horse die!!!!

 

Anytime you want to!

 

So after you change your oil, how much do you put back in your tank at any one time? Can you tell any difference in how it runs? I just changed mine over this past weekend, and I went and drained my oil at Autozone. Maybe I should have kept it.

 

I put 1qt for every 10 gal (40:1). In reality I actuall dump the used oil back into the gallon jugs it comes in then with every 34 gal fill up I pour one in - pour the oil in first then the diesel or it will burp and run down the side of your bed - black oily nastiness. You won't even know it's in there. I've burned about 50gal of used oil in the last 38k miles. Ghange the fuel filter every 20k. I run 13oz of Diesel Performance fuel treatment every other tank or every 3rd tank depending on the situation (how much time I have). Dodge says you can burn up to 5% used oil in this engine - that's 7qts to 35gal diesel. (do a search - someone posted the spec from Cummins on this) Their Industrial and OTR engines are rated to burn up to 20% used oil. I have burn 3 gal used oil w/31 gal diesel. I was on a hwy trip and noticed no issues or smoke.

Talk to your friends and tell them to bring you their used oil. Tranny fluid is the best. It's loaded with detergents thet will really clean out your fuel sys.

 

Cummins says otherwise :

http://www.cummins.com/na/pages/en/p...2180C4A8F00000

 

FASTZILLA are you putting Rotella Syn in your fuel tank? I heard that the Syn doesn't burn well. Do you filter the used oil at all before burning it?

 

I can't speak for the used motor oil, and I am curious about using it in the tank myself if it was dyno, but I understand that the tranny fluid is bad for the high pressure fuel systems these new diesels use.

 

At HIS MILEAGE anytime he wants to!

 

I'm real strict about the oil change. I only use 1 certain oil pan that is covered and cleaned before and after every use. I have never noticed anything (knocking, pinging, smoking, etc.). I don't know about the tranny fluid being bad for fuel systems. I know it burns hotter than diesel but it's so diluted that the effects should not be noticeable. The syn burns great - and by great I mean I don't know/can't tell it's in there. I'm sure there is a point where it would be noticeable but I think that would be around 5:1 or 4:1 in a hot climate, colder climates should, theoretically, be less tolerant. I also feel the higher performance your engine (higher RPM) is the more you will notice it. After all oil won't burn as fast as diesel.

I really feel the gentle application of common sence is the best proctice concerning this.

 

at less than 10k kilometers i switched...

 

There are posts about switching on FIRST oil change and never a issue.I switched at 15k.

 

Thanks for the help guys. I'll have to try that oil in the tank, saves getting rid of it. I'll let my other dodge buddies know to. Will Chevy and/or ford let you? I know a couple of powerstuck guys at work