Engine/Transmission (1998.5 - 2002) Reduced Sulfer in Fuel by 2006

[jimnance]

By June 2006 the US EPA is mandating that at least 80% of the diesel fuel produced must contain no more than 15 PPM of sulfur in road diesel fuel. Quoting from Transport Topics "Current EPA regulations allow for 500 PPM of sulfur. " Prior to 1993 sulfur content was not regulated and sulfur averaged 3,000 PPM.



Why is this important? In 1993 there was a rash of fuel pump failures in older commercial diesel trucks after low sulfur fuel was introduced. Mostly older pumps were affected which had rubber O ring seals that needed the sulfur to maintain thier integrity. Also, sulfur acts as a lubricant in diesel fuel helping to protect parts of the fuel system in direct contact with the fuel.



Sweden intoduced VLSF (very low sulfur fuel) in about 1995. A rash of fuel pump failures caused Bosch to investigate. What they found was that the fuel pump impellors were experiencing rapid wear due to the lack of sulfur's lubricating properties. In part the problem was solved through pump reengineering, and fuel reformulation.



What does this mean for us? While Cummins and others have been working to prepare thier future engines for VLSF, many of our older engines' fuel systems may suffer premature failure. While we hope that refiners will add lubricity enhancers to help prevent these problems, some engines may still be affected.



It may be a wise protective measure during the early stages of VLSF to add fuel additives containing lubricity additives until the full scope of the problem is seen. Hopefully it will not be wide spread, but treating fuel in the short term (perhaps a year) could be cheap insurance against pump failure

 

[Texas Diesel]

That is exactly why I add 2 cycle oil to the fuel at 200:1

 

[RCook]

Here's a recent post from Alex Hirsekorn, who is a regular contributor to the trawler (cruiser) boating e-mail list I follow, and is very knowledgeable in fuels and oils:





While it's likely that the new regs will do some damage to your wallet

it's unlikely that your engine will suffer.



Sulfur in diesel fuel is a pretty much universal bad actor. It's not

only bad for the environment it's also bad for your engine. When the

sulfur in the fuel burns it ultimately leads to the formation of

sulfuric acid; acid rain in the environment and acid attacking the

bearings in your engine.



Sulfur got an undeserved reputation as a lubricant when the first

sulfur reduction regs went into effect because the new lower sulfur

fuel had lubricity problems that were unforeseen by the oil companies.

Those problems did not stem directly from the lack of sulfur. They

were caused by the oil companies using a new process (hydrocracking)

on diesel production. The process changes resulted in a number of

things, some intended some not:

1. Reduced sulfur at an acceptable cost [intentional]. I don't really

understand the processes involved but sulfur removal to 0. 05% by the

older methods would have been god-awful expensive. Hydrocracking

somehow gets around the problem. I believe it also increases the yield

of diesel from a given quantity of crude.

2. A change in the molecular make-up of diesel from almost entirely

aliphatic to a more aromatic blend [known but perhaps not fully

considered].

2a. Loss of lubricity [unintentional]. Aliphatic molecules are good

lubricants while aromatics are not.

2b. Shorter 'shelf life' [unintentional]. Aliphatics are more

chemically stable than aromatics.



In hindsight the oil companies probably should have anticipated the

lubricity problem but the industry's mind set at the time had been

that lubricity was simply not an issue. Back in the 80's I was told by

one of the most knowledgeable guys in the entire industry that ANY

liquid would provide sufficient lubricity for a diesel engine's

injection system. Obviously that was incorrect but it gives you some

idea of the collective thinking at the time. As we all know, that

industry mistake broke some engines and cost the oil companies some

pretty hefty financial settlements as well as loss of face among their

customers. The oil companies did learn from their mistake however, and

the fuel you buy today already has lubricity additives in place.



I haven't followed California's fuel regulations but if, as Jim says,

this additional reduction in sulfur content is a case of the off-road

fuels (marine fuel is a subset of off-road fuel) being brought to the

same level as the existing on-road fuels then it's a sure bet that the

'law of unintended consequences' has already been dealt with. The

immediate concern of lubricity problems should be a non-issue. OTOH:

The shelf life issue could be worth considering and when the new regs

go into effect it will be more important to think about using fuel

stabilizer additives in situations where the fuel is not used up

quickly. Recreational trawlers are a prime case of that given that

most of these vessels are quite fuel efficient and also have fairly

large tankage.



The bottom line is that your engine will be fine, you'll probably want

to use some sort of fuel stability additive, and you may be able to

visually pick up Catalina Island at a bit longer range than before.

 

[Texas Diesel]

Great post, thanks!

 

[Hohn]

Anyone who's every seen real powdered sulphur can't help but wonder how the myth of sulpuric lubrication got started.

ULSD will be a good deal all around. Sulphur is NOT a lubricant!

ULSD when additized will have MUCH better lubricity than the older high sulphur "good" diesel :rolleyes

jlh

 

[Gary - K7GLD]

From this same subject over in the 3rd gennie forum:





"From everything I've read from big refiners like Mobil, Chevron, and Marathon they are developing additive packages that ensure no change in lubricity of the fuel. I'm much less worried about it now. "



TRUSTING our stateside refiners to "do the right thing" regarding diesel fuel quality is something *I* am not prepared to do! At least not until a working method is developed to hold those refiners and the EPA accountable financially for damage to equipment and/or deviations from clearly established government standards for fuel...



That hasn't happened yet, and I certainly am NOT holding my breath WAITING for it to happen! We have had abundant examples, supplied by Bosch and others, that our stateside fuels vary considerably in contaminent levels and delivered quality to the end consumer, and in MANY cases, little/no government standards even EXIST to assure diesel quality!



I, for one, don't have any serious hopes things are likely to change in one short year...

__________________

 

[jimnance]

Richard, I really oversimplified the issue, but indeed, the refining process of removing the sulfur was found to be the main problem. They ultimately worked around the problem, but going from 3,000 PPM to 500 PPM is a significantly smaller reduction in sulfur (and the refining effort to get it out) than going from 500 PPM to 15 PPM. This is a huge effort to get the sulfur level down that much. I'm just hoping that the refiners are up to the task, but not convinced enough to take a chance with my expensive injection pump until significant on road testing proves that the refiners have done thier job.



The refiners are none too happy about the new standards, and unintended consequences can occur. Take for example Mobil when they introduced Mobil 1 synthetic oil to the aviation piston engine market. They bought lots of engines for owners of aircraft damaged by the product.

 

[JWBoothe]

ULSD also will allow european automakers to sell their diesels over here. Audi and VW have some pretty bad ***** TDI models that we cannot get right now since they require ULSD.



I'd love to have a little 50+ mpg VW Golf with a 150hp/290tq TDI for city commuting!!

 

[Gary - K7GLD]

Lots of folks point to the last sulphur reduction effort as though it was the ONLY major fuel fiasco in recent history - completely forgetting the shift to UNleaded gasoline, and the resulting damage to engines in operation at that time - hell, the EPA came out and flatly said they KNEW it would cause engine damage - and they didn't CARE as long as they got the legislation they wanted!



When it comes to relying upon te EPA and refiners to REALLY go the distance to safeguard vehicle owners, sorry Charlie - I'll believe it when see it, and until then will take steps of my own to safeguard my engine and fuel system...