Diesel Engine Oil Synthetic vs. Petroleum

Wyatt Earp

My '07 Powerstroke has 260,000 miles and I'm hearing that I need a better oil than the Rotella to ease the load on my injectors, especially when it's cold out.

What are your thoughts on synthetic vs petroluem-based oil?

shilowar

I'm putting Amsoil in my Cummins at the next oil change, then I won't have to change it for a long time. [^] the only reason it is still on conventional is because it had a fresh oil change when I bought it. But I just changed all the other fluids, differentials, transfer case and transmission to synthetic.

We run Amsoil in our patrol cars and they get 18,000 miles between changes with a filter change at 9k and that's hard driven miles.

Sawz

Powerstroke specialist told me once, (because synthetic claims to go further between changes). Not to waste my money on it. He said the oil may last but the additives don't. such as the defoaming agent. Which is hard on the injectors when you start getting air going through. He told me to watch when I had a load on it and then pulled up to an idle it would idle rough. thats a sign of change your oil time. I was running synthetic at the time and noticed he was right I went back to Rotella and change frequently. Have 310,000 on my 97 F-350

Wyatt Earp

Oil change frequency is beyong my control in West Texas - I try to change my oil, oil filter, and air filter after every duststorm regardless how many miles since the last change...if I drive in a duststorm it gets changed.

I'm just trying to baby it to get a few more miles and avoid those $700 injector installs.

gjshaw

I have 350,000 miles on my 99 f250 with the 7.3 in it. I change my oil every 20,000 with amsoil and have since the truck had 30,000 miles on it. No problems at all with the motor. I did change all the injectors at 150,000 and went from 16 mpg back to 22 mpg. In my VW jetta it runs synthetic oil in the diesel and the first break in oil change was at 10,000. Try that with regular oil and oil changes are at every 10,000 miles for the life of the car. No question in my mind that synthetic oil is better.

KEVD18

if you've gotten 260k miles out of your 6 liter and you havent experience major problems, you got one of the good one and you're doing it right. i wouldnt change a thing.

ive heard horror stories from people who did things the same way for years with a truck, then got caught up in a "my way is better" argument and changed things and then all went to hell. something as simple as switiching oil could be the trigger to a laundry list of problems.

if it were me, i'd stay with the rotella. at 260k though, regardless of what oil you're running, you should be planning for costly repairs at some point in the near future. its not so much a matter of if certain parts are going to go, its just a matter of when and in what order.

Forkliftking

I use Super Tech 15w40 from Wal-Mart in my Cummins and it has over 250k miles. Buying into certain oils is like buying in to different types of spark plugs. All oil does the same thing. It keeps friction down and parts lubricated. None is really "slicker" than the other. Just like a spark is a spark weather it comes out of a planinum plug or the .99 cent ones. Some oils as well as spark plugs do last longer before they break down but is the added cost really worth it?

Mobuck

I wouldn't switch to synthetic in a high mileage engine. I run QS full synthetic in all our gas vehicles and feel it's my best option. I run the Jeeps 7000 changing the oil filter @ 3500. The HD pickups get changed depending on their average use but never more than the 7000 also changing the filter in the middle. If they've been pulled hard for a lot of miles or a long pull is coming up, I might change them out early. Likewise if they've been puttered around especially in the winter, I might change out the filter and add a fresh quart at 2500. Oil is darned cheap compared to engine internals.
My Son's work pickup gets changed when the dumbazz indicator says the oil's done. It usually has valvetrain clatter upon startup for several thousand miles before a change and a couple of his coworkers have had to expense for cam and lifter replacements. I won't risk it for a $25 oil change(yes, I know it's a lot higher for a diesel).