This is the first time I have heard about this. On another post ("What is the story on new diesel for USA"), I've read quite a bit on new requirements about low sulfer in diesel fuel and that oil should be added to the fuel in order to protect the fuel injection pump because sulfer is used as a lubricant. Is this low sulfer requirement current and is it true? Also, how much oil should be added to the fuel tank to lubricate the fuel pump?

Herb Rocha
82 240D
106,000

AS I UNDERSTAND IT, THIS REQUIREMENT IS ONLY FOR STATIONARY EQUIPTMENT (IE BUILDING GENERATORS PUMPS ETC.)WHILE CATIPILLAR AND OTHERS HAVE PRODUCED ENGINES FOR THIS FUEL THE LOW SULFER FUEL ARE NOT YET AVAILABLE. SHOULD NOT BE A PROBLEM FOR VEHICLE OWNERS..........YET.

We must clarify some terminology here. About four or five years ago, our government in its infinite wisdom reduced the amount of allowable sulpher in diesel fuel. At that time, older injection pumps without hardened barrels required additional oil as preventive maintenance to prevent damage. In my old 240D and 300D, this is a requirement.

Yes the "low sulpher" diesel fuel that is now being proposed is not yet in the pumps, but the "low sulpher" fuel begun in 1996 is.

About five years ago when that stage of "lowering the sulpher" started, injection pumps started hitting the clean rooms in quantity.

If you have a diesel with an injection pump built before about '93 or so, a jigger full of oil added to every tank is very cheap insurance.

Good luck,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

I was told; or maybe I just misunderstood; that MB pumps are NOT fuel lubed, but are lubed by the engines motor oil. Anyone knows for sure?

quote:

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Originally posted by LarryBible:

Yes the "low sulpher" diesel fuel that is now being proposed is not yet in the pumps, but the "low sulpher" fuel begun in 1996 is.

If you have a diesel with an injection pump built before about '93 or so, a jigger full of oil added to every tank is very cheap insurance.

Good luck,

---

Larry,

Now I am really confused. Is low sulfer diesel fuel at the pumps or isn't it? And should all owners MB diesel powered cars of pre 93 vintage be putting in a shot glass of oil in their fuel now, and if so, what type of oil and weight? This is the first time I've heard of this.

I'd also like to hear from the MB technicians that are on line on their opinion.

Thanks

One place that touches on the subject of fuel lubricity: http://www.biodiesel.org/default2.htm (select option 12 Low Blend -- Frequently Asked Questions) gives some insight.

The level of sulfur content in diesel fuel has been decreased in recent years; but there are EPA proposals to decrease it to much much less than it is now.

As I said, the sulpher content went down about five or six years ago. It will probably go way down again soon. Watch out for injection pump failure when they take it the next step. If you have an early diesel, particularly a 123 based diesel or earlier, that has not been upgraded with hardened barrels, add just an ounce or two of oil with each fillup.

You don't have to get crazy with this. You can use ATF, or you can use about any engine oil. Just use CLEAN engine oil, don't get the idea of recycling your drained oil this way. If you had some sort of really good filter, you could probably get by with that. But you need so little oil, that you can just buy cheap oil for this purpose. I would not use rerefined oil.

Some time ago, I bought a case of Jet 30W cheapo engine oil and it has lasted a few years, and I still have some left. It actually looks like decent oil. When you purchase the premium oils, your really paying for the additives. You don't need additives for this purpose, just a small amount of clean oil.

Good luck,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Would using the Red Line Diesel Fuel Catalyst additive with each fill-up negate the need to add the oil?

Good Question, DerBenz...
Red Line does have a lubricant... or at least it says it does....

However, even if Red Line does provide proper lubrication, it would be a LOT more expensive to use than Larry's suggestion of simply adding an ounce or two of clean oil -- even the cheap stuff!

Just savin' my $.02

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William
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles

I would suggest using the additive occasionally, but all you need with each tankful is just a touch of lubricity, a few ounces of cheap, clean oil will do this, for probably $.15 or $.20 per tankful.

Good luck,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

I can't imagine all the diesel drivers in europe (new and old engines) with they're extremely low sulfer content diesel fuel are slipping a couple of jiggers of ATF fluid in the tank at every fillup. They're must be some better explenation.

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-Mike
'87 300TD Turbo

I've spent about six weeks of the last four months in Europe, and the sighting of a 123 car was very rare.

For whatever reason, you just don't see very many of them on the road.

Additionally a US Diesel has an American Bosch injection pump. It's a different animal , made in a different plant. I don't know if this has anything to do with it. But, I do know that the American Bosch pumps were failing about five years ago, when they lowered the sulpher content in diesel fuel in this country.

Good luck,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Hey all,

I posed this question about the sulfur content and additional lubirication additives in #2 diesel fuels, to BP and Citgo petroleum companies.

I wanted to hear what the refiners have to say (officially) about their products. I will keep you posted as to what I find out.

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William
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles

I got this response from Citgo's Pam Ward, Senior Lab Engineer:

Only CITGO's Premium Diesel contains a lubricity additive, just in case. However, most diesel fuel does not require a lubricity additive. CITGO produced diesel has been tested and found to exceed the minimum lubricity requirements as measured by the SBOCLE test.

You should be able to use our diesel fuel without concerns.

I guess we can worry no more about lubrication in our fuels....


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William
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles

William,

Thanks for the research.

A diesel injection pump costs hundreds of dollars to replace or rebuild. My case of cheap clean oil cost $10.

When they lowered the sulpher content five or so years ago, the pumps were hitting the clean rooms in droves. The pump in my old 240D has never received the hardened barrels. I expect that the response you received was test results regarding late model pumps and barrels. Therefore I will continue to use my $10 case of oil, to ensure protection of my multi-hundred dollar pump.

Thanks again for the research,
Larry