Any reason I can't run diesel oil?

Topic: Any reason I can't run diesel oil? (Read 3082 times) previous topic - next topic

Any reason I can't run diesel oil?

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.

Any reason I can't run diesel oil?

Reply #1 – 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.

Any reason I can't run diesel oil?

Reply #2 – 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...

Any reason I can't run diesel oil?

Reply #3 – 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

Any reason I can't run diesel oil?

Reply #4 – 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

Any reason I can't run diesel oil?

Reply #5 – 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.

Any reason I can't run diesel oil?

Reply #6 – April 01, 2009, 04:23:05 PM

If you got high mileage it won't faze it much.

Any reason I can't run diesel oil?

Reply #7 – 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...

Any reason I can't run diesel oil?

Reply #8 – 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.

Any reason I can't run diesel oil?

Reply #9 – 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

Any reason I can't run diesel oil?

Reply #10 – 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

Any reason I can't run diesel oil?

Reply #11 – 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.

Any reason I can't run diesel oil?

Reply #12 – 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

Any reason I can't run diesel oil?

Reply #13 – 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.

Any reason I can't run diesel oil?

Reply #14 – 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.