Technical => Engine Tech => Topic started by: Red_LX on April 01, 2009, 01:34:02 PM
Title: Any reason I can't run diesel oil?
Post by: Red_LX on April 01, 2009, 01:34:02 PM
I picked up 5 quarts of Motorcraft 15W-40 "super duty" oil for cheap a few days ago. It's supposed to be for diesels, but is there any reason I can't run it in my car? I've heard a lot of people run diesel oil in gassers now anyway for the extra additives.
Title: Any reason I can't run diesel oil?
Post by: 86XR7project on April 01, 2009, 01:46:43 PM
Well this just seems silly to me. Why on God's green earth would you do that? If the car says run a specific oil you should do it.
Title: Any reason I can't run diesel oil?
Post by: Thunder Chicken on April 01, 2009, 02:13:14 PM
As long as the oil meets the SAE certification for when the car was made I see no reason why you couldn't. Since these cars were made 20+ years ago I'd imagine any oil would meet those standards nowadays.
Whether you'd see any benefit from it is a different matter entirely...
Title: Any reason I can't run diesel oil?
Post by: softtouch on April 01, 2009, 02:55:07 PM
What's the API Service rating? I think SM is the latest gas engine rating. Diesel oil has C ratings like CF CG etc. Some of the older oils were rated for both, like SL/CF. The linked write up says it is better to use diesel oil in older gas engines with "flat tappets" because of the reduced level of ZDDP in SM rated oil. http://www.aa1car.com/library/api_motor_oil_classifications.htm
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 01, 2009, 02:56:21 PM
As long as the oil has a gas engine classification(SJ, SL, SM, etc) it's fine... Now, it's actually a good idea, especially if your still running a slider cam... Oil these days generally doesn't have the the anti wear agents(mainly zinc) as the oils of old... Been almost totally eliminated to get catalytic converters to last 100+K mi...
I generally use the Mobile 5000 just because it does also meet diesel requirements...
EDIT Dayum gettin slo, see ole softy beat me posting basically the same info... LOL
Title: Any reason I can't run diesel oil?
Post by: Chuck W on April 01, 2009, 02:57:47 PM
Quote from: softtouch;265293
What's the API Service rating? I think SM is the latest gas engine rating. Diesel oil has C ratings like CF CG etc. Some of the older oils were rated for both, like SL/CF. The linked write up says it is better to use diesel oil in older gas engines with "flat tappets" because of the reduced level of ZDDP in SM rated oil. http://www.aa1car.com/library/api_motor_oil_classifications.htm
This.
I'm actually looking at using the Rotella-T stuff in the Scorp and perhaps the Volvo as they still run sliders. The Tbird had a roller, so it's not as critical.
Title: Any reason I can't run diesel oil?
Post by: Kitz Kat on April 01, 2009, 04:23:05 PM
If you got high mileage it won't faze it much.
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 02, 2009, 08:05:19 PM
This thread got me to thinking about oil classifications and amount of ZDDP.... From what I've found on the net, the last passenger car/light truck oil with a "full load" of ZDDP, is the SH classification which were replaced by the SJ oils in '01(we're now up to SM)... Now the good part, oils with the SH rating are available and will include a diesel rating of CF... So guess what??? The Mobil Clean 5000 I've been using carries the SH/CF rating(in addition to SG, SJ, SL, & SM)... Sort of makes me wonder if it really has ZDDP in it or if maybe they are using some other type of anti wear agents... Hopefully the flat tappet cam in my Lightning will continue to be protected...
Title: Any reason I can't run diesel oil?
Post by: 88FoxBird on April 02, 2009, 08:10:53 PM
Quote from: Chuck W;265295
This.
I'm actually looking at using the Rotella-T stuff in the Scorp and perhaps the Volvo as they still run sliders. The Tbird had a roller, so it's not as critical.
If you do this let me know how works out because I'm thinking about running that in the Ranger when I swap the 2.3T in.
Title: Any reason I can't run diesel oil?
Post by: 87badbird2613 on April 02, 2009, 08:23:32 PM
my friend runs a machine shop and shell rotella is the only oil he recomends from startup he said it has better detergents and anti wear stuff just my two cents
Title: Any reason I can't run diesel oil?
Post by: 20thanniver-ls on April 02, 2009, 08:36:00 PM
Quote from: 87badbird2613;265561
my friend runs a machine shop and shell rotella is the only oil he recomends from startup he said it has better detergents and anti wear stuff just my two cents
Thats also what I run in my truck and tbird
Title: Any reason I can't run diesel oil?
Post by: jcassity on April 03, 2009, 12:10:26 AM
Quote from: 86XR7project;265284
Well this just seems silly to me. Why on God's green earth would you do that? If the car says run a specific oil you should do it.
sometimes you come back with these responses based on nothing at all.
case in point,, friend of mne says engine is tapping after an oil change. he changed brands from synthetic brand x to synthetic brand y.
Its a 4.6 ,,,,,,,,,,about 80k miles.
I told him to add a little gear oil and rev up to see if the tapping stops,, if it got quiet, then its time to move up from the OEM specified 5w30 to 10w30.
problem solved, 10w40 works now due to some wear on the engine. He will probably be good to go for a few thousand miles like that until whatever happens and he decides to move up a viscosity level.
You on the other hand will continue to keep dumping 5w30 in that old motor just cause the sticker says so well into 300k miles.
Title: Any reason I can't run diesel oil?
Post by: 20thanniver-ls on April 03, 2009, 12:20:11 AM
Quote from: jcassity;265615
sometimes you come back with these responses based on nothing at all.
case in point,, friend of mne says engine is tapping after an oil change. he changed brands from synthetic brand x to synthetic brand y.
Its a 4.6 ,,,,,,,,,,about 80k miles.
I told him to add a little gear oil and rev up to see if the tapping stops,, if it got quiet, then its time to move up from the OEM specified 5w30 to 10w30.
problem solved, 10w40 works now due to some wear on the engine.
I had a similar problem on my 4.6 just last weekend. Before I changed my oil, it had a slight tapping sound, I used different oil (10w30 actually) and used this stuff called Engine Restore (it looks like a red bull can....) and no more tapping.:D
Title: Any reason I can't run diesel oil?
Post by: 86XR7project on April 03, 2009, 09:13:56 AM
Quote from: jcassity;265615
sometimes you come back with these responses based on nothing at all.
case in point,, friend of mne says engine is tapping after an oil change. he changed brands from synthetic brand x to synthetic brand y.
Its a 4.6 ,,,,,,,,,,about 80k miles.
I told him to add a little gear oil and rev up to see if the tapping stops,, if it got quiet, then its time to move up from the OEM specified 5w30 to 10w30.
problem solved, 10w40 works now due to some wear on the engine. He will probably be good to go for a few thousand miles like that until whatever happens and he decides to move up a viscosity level.
You on the other hand will continue to keep dumping 5w30 in that old motor just cause the sticker says so well into 300k miles.
Apparently I should keep my mouth shut. I have run a heavier oil in my car before but never Diesel, I'm a cautious guy I guess. I always feel like such a douche on here.
Title: Any reason I can't run diesel oil?
Post by: ipsd on April 03, 2009, 09:41:51 AM
Quote from: jcassity;265615
sometimes you come back with these responses based on nothing at all.
case in point,, friend of mne says engine is tapping after an oil change. he changed brands from synthetic brand x to synthetic brand y.
Its a 4.6 ,,,,,,,,,,about 80k miles.
I told him to add a little gear oil and rev up to see if the tapping stops,, if it got quiet, then its time to move up from the OEM specified 5w30 to 10w30.
problem solved, 10w40 works now due to some wear on the engine. He will probably be good to go for a few thousand miles like that until whatever happens and he decides to move up a viscosity level.
You on the other hand will continue to keep dumping 5w30 in that old motor just cause the sticker says so well into 300k miles.
Here is some food for thought about that 4.6. What brand of oil filter does your buddy use. I've read many times of the cheap filters loosing some filter media and getting caught in the heads and causing a knock. Might want to check into that.
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 03, 2009, 10:46:57 AM
Quote from: 86XR7project;265635
Apparently I should keep my mouth shut. I have run a heavier oil in my car before but never Diesel, I'm a cautious guy I guess. I always feel like such a douche on here.
Well... I'll suggest IF you really don't know about a subject, set back and see what is posted, you'll usually learn something and not have egg on your face...
The 4.2 in the '99 E250 I drove at work sounded like hell on 5w-20, but was smooth as silk on 10w-40... I always specified the heavier oil when it was changed...
Title: Any reason I can't run diesel oil?
Post by: 86XR7project on April 03, 2009, 10:52:09 AM
Quote from: TurboCoupe50;265652
Well... I'll suggest IF you really don't know about a subject, set back and see what is posted, you'll usually learn something and not have egg on your face...
The 4.2 in the '99 E250 I drove at work sounded like hell on 5w-20, but was smooth as silk on 10w-40... I always specified the heavier oil when it was changed...
Will do. :bowdown:
Sorry for being a dipsh*t guys.
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 03, 2009, 08:15:24 PM
Quote from: 86XR7project;265654
Will do. :bowdown:
Sorry for being a dipsh*t guys.
That's OK but don't it happen again, or we'll send Louie by to break your typing finger(s)...:rollin:
Title: Any reason I can't run diesel oil?
Post by: gumby on April 03, 2009, 09:13:57 PM
i put 15w40 rotella in my tbird this year. high mileage longblock, everybody's doin it, etc. the engine picked up a solid 15psi of oil pressure over last years 10w30. on a cool morning it has 65psi on startup! kinda has me curious if im hurting my dizzy/aux shaft gears....
Title: Any reason I can't run diesel oil?
Post by: blu84302 on April 03, 2009, 10:47:05 PM
I run synthetic Rotella 15w40 in the Jetta... TURBO DIESEL!
Title: Any reason I can't run diesel oil?
Post by: Haystack on April 03, 2009, 11:46:07 PM
I always run 10w-40. There is not alot of reason to run other types of oil here. 10w40 is the only oil that is rated for less then 0F and over 100F. I have gotten close to 0F this past winter and over 100F this summer.
Title: Any reason I can't run diesel oil?
Post by: jcassity on April 03, 2009, 11:50:25 PM
Ive been using rotella since the older thread about zddp came up here,, This weekend I am going to read up on some of the stuff tom posted ,,,,if its raining outside.
Title: Any reason I can't run diesel oil?
Post by: DVP on April 07, 2009, 05:09:26 AM
I always run 5w-30 on my winter oil change, the atleast 10w-30 the rest of the year. I have always thought about more temp/ oil flow causing wear. Colder the weather the lighter the weight, the faster it moves. That is how I have always figured it. Never really thought about the anti wear agents in the oil since it isnt a fresh motor breaking in. My oil is always so nasty when I change it anyways. No matter what I do. I have changed it early, ran SeaFoam (which is $9 a can here now) though it, Lucas, nothing helps. When I got the car the oil was BLACK BLACK so how knows. Sure it isnt helping with wear.
Title: Any reason I can't run diesel oil?
Post by: 86XR7project on April 07, 2009, 09:24:22 AM
Quote from: DVP;266225
I always run 5w-30 on my winter oil change, the atleast 10w-30 the rest of the year.
Thats usually how I do it. Seems to work out okay for me.
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 07, 2009, 09:38:55 AM
Remember this guys, cold 5W is thicker than hot 40 weight... Yes you want a thin oil in the winter(especially in the colder climates), but a 10W-40W ain't going to hurt a high mileage engine... It's what I run in the '93 Grand marquis year round, but it seldom gets below the 20s here...
Title: Any reason I can't run diesel oil?
Post by: 86XR7project on April 07, 2009, 10:04:00 AM
Quote from: TurboCoupe50;266268
Remember this guys, cold 5W is thicker than hot 40 weight... Yes you want a thin oil in the winter(especially in the colder climates), but a 10W-40W ain't going to hurt a high mileage engine... It's what I run in the '93 Grand marquis year round, but it seldom gets below the 20s here...
See I never knew that.
Title: Any reason I can't run diesel oil?
Post by: DVP on April 07, 2009, 12:26:04 PM
Quote from: TurboCoupe50;266268
Remember this guys, cold 5W is thicker than hot 40 weight... Yes you want a thin oil in the winter(especially in the colder climates), but a 10W-40W ain't going to hurt a high mileage engine... It's what I run in the '93 Grand marquis year round, but it seldom gets below the 20s here...
Makes sense since it is a cold oil. But how thick would 40 be cold? We can get in single digits for a week straight then hit high 40s-low 50s the next week. Im only at 85k on my car, I still think I might bump up to 40 over summer.
Title: Any reason I can't run diesel oil?
Post by: shorangerbird on April 07, 2009, 04:48:16 PM
-well, just for stupiditys sake, which this will be, my DD Ranger you see in my sig, the cats (converters) came apart on it about 4 years ago. sucked alot of it back up into the engine as i drove because i was about 20 miles from home when it happened. its the old 2.9l and after that episode it has smoked like a freight train, blows oil out the tail pipe(because it ends up on the tailgate!) and just basically i have to add oil quite often. now, i usually keep some with me behind the seat, but i have been know to run out on occasion, so i have at times added: 80w90 gear oil, 15w40 diesel, 75w140 gear oil. trans fluid, etc.....:rollin:just to get by with something in it....get it??? not my smartest moves, but i did it anyway, because i know this things on its last leg, so i'm really not worried over its affect on the engine, BUT the dang thing just keeps rollin along, regardless of how bad its treated. boy is it bad when you come up to a stop and have to idle for a light. the burnt/hot smell is really strong. but i look forward to the day when it quits so i can transplant that 4.0 ive been saving......supercharged maybe......;)
Title: Any reason I can't run diesel oil?
Post by: Kitz Kat on April 07, 2009, 05:02:33 PM
Most diesel oil will be 15-40, If you got high milage low oil pressure it will help for a while. It's not the best to use in cold weather in a car , You might do more damage on start up. Because it does get like tar cold.
Title: Any reason I can't run diesel oil?
Post by: TurboCoupe50 on April 07, 2009, 05:30:54 PM
Agreed 15W will be a tad thick in really cold weather, but I ran Castrol 20W-50 in my Cobra Jet for years and the bottom end is yet to be pulled apart...
They mostly only specify the thin oils in the newer engines to increase gas mileage... Thinner equals less splash resistance and less oil pressure, so the pump has less drag... Internal clearances are tighter on newer engines, so I would not use something like a 15W-40 till it had 60-70K miles, but wouldn't hesitate to use a 10w-30 in the summer... Last summer I was using half 5W-20 & half 10W-30 in my 20K mi '07 Grand Marquis... Changed it in Dec and used all 5W-20, it clatters on that stuff almost as much as the 4.2 in the '99 E250...
Title: Any reason I can't run diesel oil?
Post by: Kitz Kat on April 07, 2009, 06:14:33 PM
The reasons for thin oil is tight bearings, Old loose bearing will be helped by thick oil.