Talking to an Audi rep, and Diesels in the US

Doyt W. Echelberger doyt at
Fri May 12 22:05:11 EDT 2006

At 07:53 PM 5/12/2006, you wrote:
>Where I'm not clear is what happens to the older engines when they're
>subjected to a diet of low sulfur diesel? Can you imagine the havoc
>that will be caused if the US's fleet of delivery vehicles suddenly
>come to a halt?
>Sean [99 A6 2.8q]
The US diesel fuel industry 'reduced' the sulfur in its fuel years ago, and 
it caused problems with the injector pumps. They didn't go to the very low 
levels that are prescribed for September, but they dropped it enough to 
ruin lots of injectors pumps.

When used in earlier model US diesel imports (such as the VW Rabbit and 
Jetta up into the 1990's)
reduced-sulfur diesel caused serious wear to the very expensive fuel 
injector pump......500 to 600 dollars to rebuild.

The sulfur acts as a lubricant for the very close tolerances inside the pump.

We who drive such older cars dope our fuel with additives that supply 
necessary lubricity....Stanadyne makes such an additive, as well as many 
others manufacturers. Truckers also use the lubricity additives.

When the new very low sulfur fuels are the only alternative, additives will 
be in far greater demand by the owners of these older diesels. They will be 
paying for the fuel manufacturers to take out the sulfur, and then paying 
the additive manufacturers to put it back in.

I don't know about the late model US diesels, such as the current 
generation of TDI by VW. They probably have injector pumps that are made to 
run on reduced-sulfur fuel....but possibly not LOW sulfur fuel.  Maybe the 
TDI web site would address this.

Doyt Echelberger  

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