What type of engine oil?

[Dejanh]

I used all and its the same.....

Detroit reccomends Mobil delvac and that what I use now.

[Mack2]

Explain this one, 2005 Pete 379, with a c15 Cat engine, sticker on drivers side frame rail says "Factory filled with Chevron Delo"

Why? Cat has their own oil, and I have heard from tons of Cat people that it comes in the same shipment as thier Mobil oil.

Is that a Peterbilt "factory fill?"

BTW, I personally use Castrol's Tection oil, but thats my own truck, My dad treats the others to Delvac.

Cat and Mobil oil are the same.

[no_worries]

My KW with a Cummins came factory filled with Delo as well, yet the only engine oil that Cummins specifically recommends is Valvoline Premium Blue...and that's for extended drain intervals even.