I know the 7.3L PS will handle it just fine (the farm truck is a `99 SD 7.3L PS), we use it as an oil recycling station for the tractors and cars.

The 6.0L Crapistar and the 6.6L Isuzu are toy engines and have enough trouble just keeping together at unloaded conditions. I think running anything other that premium #1 eco-friendly, specially formulated to be EPA friendly diesel might just lock them up.

Crap... Sorry for the political statement.... They will probably run it just fine. The things are all designed to run on #2 diesel which compaired to #1 is pretty crappy. Think about the ones in 3rd world countries, UN vehicles, etc. I'm sure those things will burn just about anything once they warm up.

 

The rule of thumb is 10,000 miles to change to synthetic. So if you change at 7500 I don't see much difference (first oil change). It will not hurt the motor to change earlier. It is just when you switch, your wear will be very very minimal. I made my mind up to do 30,000. Whatever you want to do. Plus I took my time on research before I made up my mind on which brand to use.

 

Please don't take this question wrong, but why would you want to go syn oil? Other than for extreme cold anyway.

I myself thought of going Valvoline syn, but decided on Delo400 last change @ 19000

Thanks!

 

From what I have seen and heard it is better on wear and tear for the moter. I do tend to see alot of cold temps up here in ak. Funny thing is if I went by the start guide on the back of the visor July and August would be the only months I woulnt have to use the special cold weather starting procedure. This is my first brand new truck and I am trying to take good care of it. At least untill I start putting mods on it even then my theroy (sp) is that quality maintnence should be better for the truck overall.

 

[QUOTE=67Charger383HP]Please don't take this question wrong, but why would you want to go syn oil? Other than for extreme cold anyway. ]

Besides the cold and hot properties (ability to stand up to both extremes without turning into sludge) it has a lower friction and you will see a slight improvement in fuel economy. I know that can be argued all day long, but you will see 1/2 to 1 mpg increase. That has been consistent in every vehicle I've driven (and changed to syn) over the last 15 yrs. Just try it one time. It will cost you twice as much as dino oil. you'll see.

 

Where does Cummins say its ok to dump 5% motor oil into the gas tank? I tried to find a related link but didn't turn up anything.
Bio is not the same as used motor oil.......

very interesting though

 

I changed mine over to Mobil 1 Syn at 1K, I've always used syn in all of my trucks but this is the first diesel I've had in about 10 years. Should I be dropping that synthetic back out until I get more miles on the truck ????

Thanks for any advice.

 

I'm sticking with the old Dino oil, by habit I usally change the oil and filter every 4 to 5 thousand miles mainly because its cheap and most of the time I have nothing better to do (retired).

 

To answer your initial question, IMO, never. I've put over 200K miles on three different CTDs, all on regular dino oil. As far putting drain oil in my fuel tank, I wouldn't even consider it. I read articles about people who visit fast food joints and scrounge their old fry oil and use that. Yuck! But, all that said, it's your truck, your money and your choice. Do whatever makes you happy.