Best oil to use, first oil change.

[CumminsKLR]

My truck has about 136k miles on it and the oil seems a bit black and nasty,so I'm going to change the oil tonight and put a new air filter on, now should I use synthetic? Any certain brand? Thanks!

[strokinpower]

My preference on a 7.3 is 15W-40 Rotella, Now that I have a 6.4 I use the Motorcraft. I also recommend getting a fumoto oil drain valve for future changes. BTW Wal-Mart seems to have the best deal on rotella and motorcraft filters... also not a bad idea to throw in a bottle of the lucas synthetic oil stabilizer...

[CumminsKLR]

So use the synthetic oil stabilizer with conventional 15-40?

[strokinpower]

yea, for whatever reason on the Lucas bottles it says to use one bottle of the synthetic stabilizer for the powerstrokes... probly because the synthetic is more expensive and there are way more powerstrokes out there than the other "diesels." So I guess they figure they can get us with it...

[CumminsKLR]

Yeah I'll probably just go ahead and use full synthetic

[strokinpower]

It cant hurt... the only negative thing I've heard about using synthetic oil is that it is so slick that it may leak where conventional oil may not (don't know how true that is...) also once you go synthetic your not supposed to go back.

[CumminsKLR]

Yeah Ive always used royal purple synthetics in everything so I'm new to the diesel thing, my truck does have a small leak that I've narrowed down to the hpop lines so maybe I'll stick with conventional until I get the leak fixed.

[strokinpower]

I thought about the Royal Purple but dang, You need 15 quarts of it and they are proud of it haha...

[CumminsKLR]

Yeah an oil change in my cobra is about $60 with only 6 quarts so I'll pass on that

[CumminsKLR]

Well just did my oil change and new k&n filter and $105 later the truck idles and runs a lot better