Oil differentiation between diesel and auto applications

[RalphVa]

I think the only difference is some detergent in diesel oils to hold soot in suspension. I used a gasoline rated oil in my 4010 for most of its 660 hours. I changed it once/year, which was only 70-100 hours vs. the recommended change frequency of 200 hours. I wanted to use a 0w30 oil, and there just weren't any (still extremely few) diesel rated ones.

The Tier 4 engines seem to be even tighter, particularly my Isuzu diesel generator engine. It's oil is still almost crystal clear at 40 hours. Also, my JD 1025's oil isn't getting as black as it did on the 4010.

So, I'd have no problems using some of the oils you have. Just run them 100 hours or less.

Ralph

 

[Soundguy]

API s is for service, and c commercial

Why risk damaging a diesel running s only, rated oil?

 

[Copperhead]

I thought "s" was for spark ignition and "c" for compression ignition?

 

[MHarryE]

I thought "s" was for spark ignition and "c" for compression ignition?

you are correct - spark and compression, dating back to the early part of the 20th century but soon to be replaced. Get ready for ILSAC. That's the International Lubrication Standard Approval Committee. The GF-6 very low viscosity oil spec will bring new oils in about the end of 2017 - spark ignition engines.

 

[hutchman]

It's sad but with every new C rating that has come out, the quality of the oil compared to older stuff has suffered. If you're running old flat tappet diesels, you have to get the best synthetic oil to equal the wear properties of just ordinary oil from 10 yrs. ago. This is due to govt emission specs.

Do your homework, old equipment may need a ZDDP additive just to make today's oil as good as it used to be. I've read that gasoline oil has as much (or more) ZDDP, phosphorous, molly etc. as today's diesel oil!

 

[Soundguy]

you are correct - spark and compression, dating back to the early part of the 20th century but soon to be replaced. Get ready for ILSAC. That's the International Lubrication Standard Approval Committee. The GF-6 very low viscosity oil spec will bring new oils in about the end of 2017 - spark ignition engines.

please see page 2 of this PDF if you feel the need to contradict me..


S is for SERVICE

C is for COMMERCIAL

http://www.api.org/~/media/files/ce...iesel/publications/mom_guide_english_2013.pdf

Here's the text if you won't look at the pdf

The API Service Symbol, also
known as the Donut
1. Performance Level
Motor oils designed for cars, vans, and light trucks with gasoline engines
fall under API S ( ervice) categories. Motor oils designed for heavyduty
trucks and vehicles with diesel engines fall under API C
( ommercial) categories. Please see the and
charts on the next pages for descriptions of current and
obsolete API service categories.

 

[MHarryE]

please see page 2 of this PDF if you feel the need to contradict me..

S is for SERVICE

C is for COMMERCIAL

http://www.api.org/~/media/files/certification/engine-oil-diesel/publications/mom_guide_english_2013.pdf

Here's the text if you won't look at the pdf

The API Service Symbol, also
known as the Donut
1. Performance Level
Motor oils designed for cars, vans, and light trucks with gasoline engines
fall under API S ( ervice) categories. Motor oils designed for heavyduty
trucks and vehicles with diesel engines fall under API C
( ommercial) categories. Please see the and
charts on the next pages for descriptions of current and
obsolete API service categories.

Got my info directly from API on their site explaining their system...I linked to their site earlier in this thread. Did some more research. aPI in some places references the ratings as Service/Spark Ignited and Commercial/Compression Ignited oils. So they do appear to create some confusion themselves. I found copies if the same document that differed only in how they described the S and C identifies. I remember in the 1960s when they introduced SE oil. People started identifying it as Service Extreme which they said was not their intent as it was just the next in a series. I believe that is when they started to differentiate as spark and compression.

 

[hutchman]

... Seems like 10 yrs or so ago, all motor oil was motor oil, whether the engine was diesel or gasoline ...

... I didn't get to fully develop my last post. To a large extent, what you said is actually reveresed. 10yrs ago, diesel oil in many ways was better then than today. Today, gas and diesel oil are closer than they probably have ever been.

It used to be a good diesel oil had a high TBN to start with and had the ability to stay high during extended change intervals. It also had very high numbers in Calcium, Phosphorus, Zinc etc. Today, diesel oil has way less of these due to emission specs (ULSD, DPF etc.). Those Uber wear additives produced more ash which isn't kind to DPF, catalytic converters and so on.

Since most modern engines use roller lifters these days, oil companies cheat to meet govt. specs without telling the customers that their engine is wearing more than it used to!

If you're like me and have 4 flat tappet diesels to keep up, this matters to you. To get the same protection you used to be able to get ... you have to use racing oil (exempt from API) or add things like ZDDP Or run the most expensive full synthetic you can (which still has marginal wear additives compared to the earlier specs like CI)

 

[Copperhead]

But there are other elements that have been added to modern oils that have been very effective in complementing lower levels of zinc. Boron and moly come to mind. Boric Acid makes oil much more "slippery" and is extremely inexpensive to make, and Moly ( MoS2 ) has some very unique qualities being a flat structure, hard plate element that significantly reduces metal on metal contact with no build up. In some cases, a much better anti wear metal than zinc.

Moly articles...

Moly Basics - Bob is the Oil Guy - Bob is the Oil Guy


Not sure if your contention that motors are wearing faster with the new oils. Detroit has upped their recommended oil change interval for DD15 commercial duty semi truck engines to 50,000 miles or 10,000 hrs. I took a Cummins N-14 to well over 1.4 million miles with no problems other than one fuel injector and one accessory drive seal and it got 30,00 mile oil changes. All on CI-4+ and CJ-4 oil and no bypass filter.

 

[buickanddeere]

What is the desire to try and out think the mechanical and chemical engineers that designed the engines and the lube oils ?