Oil Advice Needed

Reply Subscribe

Thread Tools

Search this Thread

Nov 25, 2008 | 12:03 AM

#31

mercman86

Elder User

Joined: Feb 2008

Posts: 783

Likes: 1

From: Chicago Area, Illinois

All i use in the marine industry for inboard engines is 25w-40. Mercury Marine makes this (its manufactured by citgo) it is formulated for long use at high rpms. Like i said is thats what is used in all mercury inboard engines. The reason why the factory dosent advocate using automotive oils is that the 25-40 has extra friction modificators in it to keep deposits from forming and to reduce wear. lol as part of my certification they make us take a 5 day long course on lubrication and oils!

Nov 25, 2008 | 11:18 AM

#32

jimandmandy

Post Fiend

Joined: Jun 2001

Posts: 5,228

Likes: 5

From: Running Springs CA

Quote:

Originally Posted by wterlwms

I live in san antonio, tx and have a 2003 F-350 turbo diesel which the owner's manual say to use 15w-40. I would like to start using synthetic, but can only find 20w50. Can 20w50 be used without fear of some kind of engine damage? The truck has approx. 40,000 original miles.

Thanks,

Walt

I'm a bit concerned. 20W-50 is not a common grade of synthetic nor diesel-rated oil. What brand did you find?

Your engine requires API CI-4 as a minimum. The Powerstroke injection system is unusual as it uses oil pressure to fire the injectors. It is vital to use the correct oil. 5W-40 Rotella T Syn is the most commonly available syn that meets the spec.

Jim