Diesel oil vs gasoline engine oil

Speakrdude

Ensign
Joined
Feb 25, 2004
Messages
942
I just went and picked up my single cylinder Diesel (Kubota EU300) block for my genset from the engine rebuilders. New Piston, sleeve, bearings, guides, whole 9 yards.

Anyway, I need to put oil in it. (all 1.4 quarts of it.) I have never owned a diesel engine before so I have no clue what kind of oil to buy.

I went to the local Oreily Auto store with the service manual in hand and asked for help with the oil. The manual calls for a 20, 30. 10w30 oil. The clerk suggested I use a regular gasoline engine "synthetic oil" and most all oils are above the diesel oil specs nowadays. I have my doubts before I ruin a $1000.00 rebuild.

Thoughts?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Diesel oil vs gasoline engine oil

DON'T put a synthetic oil in a brand new engine... You need a run-in oil...

As for running gas engine oil in a diesel... not a great idea.. Running diesel oil in a gas engine... no problem.

I read a thread in a motorcylce forum MANY years ago about oils... I'll hunt it down and post a link... REALLY informative... and well worth the read... (stay tuned....)

Ok.. the website doesn't exist anymore... Not surprised, it was 2005. I have it as a PDF. If you'd like a copy, PM me with your email address and I'll send it to you...

Chris......
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: Diesel oil vs gasoline engine oil

Lots of diesel guys use Rotella engine oil.
 

windsors03cobra

Lieutenant Junior Grade
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Feb 22, 2009
Messages
1,191
Re: Diesel oil vs gasoline engine oil

I would use a diesel oil, Chevron Delo, Castrol Tection, Mobil Delvac and Shell Rotella are names that come to mind.
 

Jeepster04

Chief Petty Officer
Joined
Jan 5, 2009
Messages
481
Re: Diesel oil vs gasoline engine oil

You can get a 4 quart jug of 30w Rotella at Walmart. Been thinking about using it in our boat engines from now on.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: Diesel oil vs gasoline engine oil

use a nice quality 15w-40 and you have no problems.

Chris, if you have the pdf email it to me if you get a chance. i'll pm you the email.
 

rthomas

Petty Officer 2nd Class
Joined
Nov 9, 2007
Messages
155
Re: Diesel oil vs gasoline engine oil

diesel oil for diesel, gas oil for gas,-its the additives that make the difference. diesel oil has different additives to help deal with soot and unburnt fuel, that is very important because soot can be very abrasive. I run chevron delo 400 in my work trucks
 

rbh

Fleet Admiral
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Mar 21, 2009
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Re: Diesel oil vs gasoline engine oil

The diesel motors in our trucks take 15-40, the gensets take 30 weight in the summer and 15-40 in the winter.
 
D

DJ

Guest
Re: Diesel oil vs gasoline engine oil

Choose the viscosity your engine spec's. 30, 15W-40, etc.

The API classification should be: CJ-4.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Diesel oil vs gasoline engine oil

AFTER it's thoroughly broken in, you can extend the service life of the engine by running synthetic in it. Never run a synthetic oil in a new engine because it has such a good film strength that it can prevent the engine from wearing the parts that need to be worn for break in.
 

JRJ

Commander
Joined
Sep 11, 2001
Messages
2,992
Re: Diesel oil vs gasoline engine oil

Run what the manual says. I use Dello 400 in my Cummins.
 

pmat1

Petty Officer 1st Class
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Jul 9, 2009
Messages
332
Re: Diesel oil vs gasoline engine oil

only difference with gas and diesel oils is that diesel oils have more cleaning additives. i would still reccomend diesel oil. and NOT synthetic until its broken in.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
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Messages
26,019
Re: Diesel oil vs gasoline engine oil

Do not be surprised if the oil looks completely BLACK real fast (like after the first day)...... that is common with diesels.
 

Speakrdude

Ensign
Joined
Feb 25, 2004
Messages
942
Re: Diesel oil vs gasoline engine oil

How many hours are in a good break-in period to change the oil for that little guy?
 

642mx

Lieutenant Commander
Joined
Apr 19, 2008
Messages
1,588
Re: Diesel oil vs gasoline engine oil

AFTER it's thoroughly broken in, you can extend the service life of the engine by running synthetic in it. Never run a synthetic oil in a new engine because it has such a good film strength that it can prevent the engine from wearing the parts that need to be worn for break in.

Thats an old wives tale. Lots of engines have synthetic oil in them from the factory.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Diesel oil vs gasoline engine oil

Thats an old wives tale. Lots of engines have synthetic oil in them from the factory.

And lots of engines are glazed over from not being broken in. It's a big deal with 2 cycle merc engines.

I don't claim to be an expert, but I do claim to be old.:D

John
 
D

DJ

Guest
Re: Diesel oil vs gasoline engine oil

I don't claim to be an expert, but I do claim to be old.:D

That is terrific. But, you know what, us "old dudes" actually do know some things.

"Experience is the best teacher yet. "It takes 30 years to gain 30 years worth of knowledge".

But, I'm always open to new ideas. That's the difference between a dinosaur and a visionary.
 

skargo

Banned
Joined
Sep 14, 2008
Messages
4,640
Re: Diesel oil vs gasoline engine oil

Thats an old wives tale. Lots of engines have synthetic oil in them from the factory.

Yep, I had a Vette that came with Mobil one synthetic in it.
 

Bob_VT

Moderator & Unofficial iBoats Historian
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Re: Diesel oil vs gasoline engine oil

ALL the new Corvettes come equipped with synthetic oil ;)
 

gss036

Commander
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Jan 18, 2003
Messages
2,914
Re: Diesel oil vs gasoline engine oil

SO, did my new Jetta and they do the maintenance for 3years using synthetic.
 
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