Your preferred diesel oil?

[Honeyman]

Ok, we argued about warming up our diesels, I'd like to hear from others about their preferred oil they use to lubricate that diesel. My 3GM30F manual is so old it recommends API service class CD oil. That "class" is obsolete and there are now several recommended for diesels including 1 that mentions "for use with fuels with less than 0.5% weight sulfur(CG-4) or up to 0.5% weight sulfur (CI-4 or CH-4). With the recent discussion on ultra low sulfur fuel, looks like it may be important to pay more attention to service class. Comments?

 

[Steve Dion]

Delo 15-40

I have been using Delo 30 or 15-40 for many years. The reason for using Delo was the availability of the product. Originally Yanmar recommended 30wt for the GM series, but has since changed over to also recommend 15-40 oil.I just pick up Delo and assume that they are with the current standards, so I do not need to worry about which iteration of the SAE Cx I am purchasing.

 

[seadaddler]

Walmart-shell 15-45

I am sorry its shell 15-45 ro something thing,some one will help here while I have a senior moment but anyway that's what I would use or 30 on an older motor for sure.

 

[ConchyJoe]

I remember using Delo in our farm tractors,

and hearing from the dealer that it had some suspension properties that were beneficial to diesel engines.

 

[Calif. Ted]

The Shell Rotella mentioned by Seadaddler

has been the choice for diesel fleets for many years along with the Chevron Delos. I'm using the Chevron Delos because it's available almost everywhere including Walmart etc.

 

[TT23844]

Check the archives

There was a recent post abt. lubricants that got a lot of responses: I think it was on this forum. The idea was kicked around pretty well and seemed to cover most of the issues involved. Steve identified that selection of an oil is often a matter of availability and not necessarily a suggestion that one product is superior to another. I'd say that any oil from an established, reputable, refiner that carries the correct API service classification and SAE viscosity number would be OK, but both the API & SAE data have to meet or exceed the spec. given by the engine mfg.  CE is "better" than CD; CF "better" than CE, and so on.  Older engines were designed before multi-grade oils were readily available, so their spec. will call for a single weight oil, say a SAE 30. A multi-grade oil would usually be an acceptable substitute and probably is more readily available, but there may be a few exceptions to this. Bear in mind that when two numbers appear for the SAE viscosity, the first number refers to the cold start viscosity and the second, the viscosity at operating temperature.So if the engine calls for a SAE 30, then a 10W-30 should perform the same and have the same properties when hot, but a 10W-40 may be too "thick".Don't know abt. API CH-Plus or CI-Plus, but if you're using a LSD or ULSD fuel I'd contact a distributor or the oil co. and ask abt. compatibility of your prefferred oil to the fuels.

 

[caoitybill]

stainless steel oil filter-any good?

trying to determine if it is safe to use a washable stainless oil filter in a diesel truck? (f250 2003)

 

[Paul Akers]

CD?

Although CD has gone by the way (still available thru WM), you can use ANY later version greater than CD (e.g. CE, CF, CG. etc.) . Just watch your viscosities.

 

[Phil]

Most oils

Most high grade motor oils are fine for diesels. If it makes you feel better you can get one that has diesel printed on the front.

 

[Benny]

Older engines may benefit

from a heavier oil. 20-50 may restore some compression to slightly worn engines.

 

[TT23844]

C'mon, Benny

A thicker oil may provide some benefits when the crank & rod bearings are worn and/or the oil pump is tired, as the clearances in those components is greater due to wear. I cannot see how going to a 50 weight oil will benefit the compression, which is dependant on the effectiveness of the seal provided by the valve seats and the piston rings. Phil- "Printing diesel on the front" means little. It's the API/SAE rosette that is the guarantee of performance. An oil that's got an API classification beginning with the letter 'C' is formulated with additives etc designed to address the sulphur etc that are the by-products of the combustion of diesel fuel. Using "any high grade motor oil" as you suggest may get you by for a long time but to completely ignore the API classifications and buy oil intended for gas engines doesn't seem to be a very well thought out position to take.I don't know of any hard numbers or data to support this, in terms of "you'll get X number of hrs. engine life if you use Lube A, vs Lube B" , and if an engine is well maintained and used intelligently, we may be splitting hairs, but it seems stupid to ignore the efforts of trained engineers and chemists etc who make the lube oil specs. and take an ill-informed, anecdotal approach to selecting lubricants. The 'up-front' costs of using the specified products are essentially the same. What's the benefit in ignoring them ???

 

[Phil]

Rough up North?

TTI am sorry. In the future I will check directly you. I am going to throw out the manual which came with the boat and I am deleting the number of my truck diesel mechanic since he is stupid.Also, what I said was that, "If it makes you feel better you can get one that has diesel printed on the front."Having a rough winter up there?

 

[Big Windy]

Oil/ULSD

Shell Rotella 15w40 for oil. Also, the engine oil has nothing to do with the new ULSD fuel. The lubrication provided by the sulfur in the diesel fuel is for the fuel system, not the engine lubrication system. FWIW, the word on the diesel engine truck forums is that the new fuel will have adequate lubrication added to replace the lubrication formerly provided by the sulfur.

 

[Old Salt]

I agree with TT

I don't think his response was unreasonable, like he said they "may be splitting hairs"Although there is a difference between "C" and "S" rated oils. (Incorrectly assumed to be C for Compression (Diesel) and S for Spark (Gasoline). In fact S stands for Service (typical passenger cars and light trucks using gasoline engines) and C for commercial applications (typical diesel equipment). Ok. I am splitting hairs In reality most "good" oil (like delo or rotella) is both S and C certfied.(For instance API SG/CD or SH/CD) So its a moot point unless you have some special Marine Deisel Oil requirements (Marine Turbo Diesel??)Although if you think any old can of "SA" rated $1.00 oil is good protection for your marine diesel then you are uninformed & I'd rather not buy your boat from you in 5 years. In the USA there is a very respectable organization called API (American Petroleum Institute) and you should when you have a time visit their excellent website www.api.org which is filled with lot of consumer oriented data as well as lot of technical stuff.API is also the "rating" that can be found on most motor oils on their back labels with cryptic letters like API SJ or API SH/CF, stuff that 99% of consumers have NO IDEA what it means or represents, and nor do majority of car mechanics.You can go to API web and spend time to educate yourself about what it all means. Or you can spend $109 to purchase latest copy of API 1509 document (15th Edition) that will give you all the technical and legal specific for each current API "S" or API "C" motor oil rating.Standard Engine Oil Licensing and Certification System Edition: 15th Revision #2Document Number: API 1509 American Petroleum Institute 01-March-2002 72 pagesHardcopy Price: $ 109.00 Download Price: $ 109.00 Should you be interested it is available from APIOR you can go to a few of these links which are actually easy reading with interesting stuffhttp://www.carbibles.com/engineoil_bible.htmlhttp://www.bobistheoilguy.com/http://www.micapeak.com/info/oiled.html

 

[Benny]

Where can I get a copy of that API book?

It would make wonderful reading in these balmy winter nights here in Florida. The smartest point I have heard is the assertion that this may be a moot point as all "the good oils" seem to meet the necessary rating for general, non-specialized diesel engine applications. TT does not mention all the components for compression. He mentions piston rings but omits the cylinder wall and the film of oil in between the two. Older engines usually suffer from reduced compression due to wear of piston rings and cylinder walls. This can be observed as compression blow-by into the crankcase. Pull your oil dipstick while the engine is running and if you feel air pushing out that is a portion of the compression force getting past the rings. The stronger the force the more compression you are loosing. As the mechanical parts wear down a thicker oil will contribute to restore the balance between the three. To discard the effect of oil in compression is to negate one of its most important functions in combustion engines. I did not claim it was a miracle cure but stand by the assertion that going to a heavier oil can benfit the compression of a slightly worn engine. STP and other lubricant additive companies have made a bundle over the years selling oil additives to restore engine compressions and quiet noisy valve trains.

 

[Big Windy]

C vs S

Old Salt..."Although there is a difference between "C" and "S" rated oils. (Incorrectly assumed to be C for Compression (Diesel) and S for Spark (Gasoline). In fact S stands for Service (typical passenger cars and light trucks using gasoline engines) and C for commercial applications (typical diesel equipment). Ok. I am splitting hairs." According to Nigel Calder (page 253 of his Boat Owner's Mechanical And Electrical Manual): "The American Petroleum Institute uses the letter C (for compression ignition) to designate oils rated for use in diesel engines, and the letter S (for spark ignition) to designate oils rated for use in gasoline engines."

 

[Rick D]

Old Salt vs. Nigel

I think Old Salt won that round. See the API site. C does in fact indicate 'Commercial' however, if you go on, you'll see that generally refers to diesel application. Like the salty one said "probably splitting hairs". There's enough here for gearheads to pig out on for some time. Enjoy. Rick D.