Oil?
Post Fiend
Joined: Feb 2009
Posts: 8,005
Likes: 7
From: Ottawa, Ontario
They say it depends on how cold it gets where you are. I keep 15W-40 year round, even though I've seen temperatures go below -24*C (-10*F). When it's really cold I think you can run 10W-30, but someone can correct me on that.
Elder User
Joined: Sep 2009
Posts: 693
Likes: 1
From: Indiana
Well, if you are running a 7.3 diesel, I would only consider 15w40. If you were in like minisoda or something like that where the temperatures were quite extreme then I would run 5w40 rottella T. Its synthetic too. But, only if you were in an extremely cold area. 15w40 should suit you well otherwise. no 10w30. That is gasoline motor oil. It will not withstand a diesel engine. Instead the sulfer will turn it into like paint thinner. Only use diesel engine oil in your diesel. But, I do use diesel engine oil in my truck.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
When the IDI was produced the API service designation was SF/CD or SF/CE.
The part important here is the C, compression ignition.
Temps from 0 C or 32 F and higher, SAE 30
Temps -18 C or 0 F and up, SAE 15W-40
Temps 32 C or 90 F and below, SAE 10W-30
Ratings like CI-4 or CJ-4 and all those are for engines using high pressure oil to fire the injectors so it don't foam when released from the extremely high pressures in the injection system.
The part important here is the C, compression ignition.
Temps from 0 C or 32 F and higher, SAE 30
Temps -18 C or 0 F and up, SAE 15W-40
Temps 32 C or 90 F and below, SAE 10W-30
Ratings like CI-4 or CJ-4 and all those are for engines using high pressure oil to fire the injectors so it don't foam when released from the extremely high pressures in the injection system.
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Elder User
Joined: Sep 2009
Posts: 693
Likes: 1
From: Indiana
yeah, as long as in the api oil doughnut, it has a "c" rating as well you can use it in diesels. Other wise you must resist all temptations to use it if it is just gasoline oil. You can run diesel engine oil in gas engines, but never run gas engine oil in a diesel. What I refer to as the api oil doughnut, is the circle that has info such as: 15w40 sm/cj-4, energy conserving. This is how you find oil that is rated for your needs.
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Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
If I were ever where my choice was gasoline (S for spark) rated oil or no oil, the gasoline oil will go in the engine.
But it will also get changed as soon as possible.
Gasoline rated oil do not have a detergent package that can handle the soot, or the suspension additives that keep the soot from being deposited in the engine.
But it will also get changed as soon as possible.
Gasoline rated oil do not have a detergent package that can handle the soot, or the suspension additives that keep the soot from being deposited in the engine.
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