There are many rumors circulating about the effects of sulfur being in diesel fuel or sulfur being taken out of diesel fuel. Diesel fuel without sulfur is just as good, in all respects except one, when compared with today’s fuels with sulfur. Diesel fuel now must meet a lubricity standard. The producers adjust the lubricity before they distribute the fuel. No further additives are needed to ensure proper fuel system lubrication.
The only negative effect of taking sulfur out of fuel is that the fuel becomes more expensive, somewhat negating the inherent cost advantage of running diesel engines when compared to other fuels. As we are certain you know, sulfur doesn’t jump out of the fuel on command. It has to be removed using specialized equipment and chemical processes that add to the expense of producing the fuel.
We have seen very few instances where the reduced aromatic content of the fuel has resulted in slight leaks from fuel systems. This is not expected to be an issue with many engines. Basically the change to new fuel should be pretty easy for folks with the engines built prior to 2007 and for customers with the engines built in 2007 it will be necessary, for the short time it takes fuel stations to consume the remainder of the old fuel (maybe a month or two), to be certain they are not fueling with the older fuel.
There is an effect on diesel engines from the use of low or no sulfur fuel which we expect to be positive. The blowby gasses that normally pass through the engine crankcase will contain less or none of the chemically reactive sulfur and its compounds. This will tend to keep the engine oil cleaner during operation and allow important engine components like bushings, bearings and piston rings to live longer. Diesel fuels containing sulfur or no sulfur each have the same specific heat, about 20,000 BTUs per pound. For that reason, they give the same amounts of work for the same amount of fuel. That means the fuel economy per gallon will not be affected. Over the years we have seen fuel economy decrease, somewhat, as diesel engine designs have been modified to meet the lower NOX limits imposed by the government. This has been totally unrelated to sulfur in the fuel.
With lower sulfur fuels it is possible that some exhaust after-treatment devices (catalytic converters) may be used to better effect, making it possible to further decrease harmful exhaust emissions. If you use diesel fuel that does not meet the new federal low sulfur requirements that are going into effect for 2007, in a 2007 vehicle that requires the new fuel, it will produce particulate matter that will cause rapid plugging of the exhaust particulate trap. We don’t anticipate producing engines for such vehicles until 2007.
You have contacted Cummins, Inc. at our Customer Assistance Center located in Columbus, Indiana.
This is our worldwide headquarters and has been our home since Clessie Cummins founded the company on February 3, 1919. *********************************************************************
Cost of Repair
1/18/07 by Vern Hoy
Last month I had my lift pump replaced‐‐it was leaking enough to leave a puddle of fuel on the ground when parked, and left the bottom of the engine and transmission quite dirty.
Cummins Irvine replaced it while I was getting other service. The pump was $259.49, + $19.56 tax ($279.05), and was difficult to replace. Labor for the entire service was (at $101 per hour) $656.50. (They figured labor to replace the lift pump was 3.5 hours but didn’t break it out on the invoice).
Thus, it cost $279.05 for the pump and $353.50 for the labor to replace the lift pump‐‐a a total of $632.55.
What else can we expect from the low sulphur diesel fuel?
2000 Foretravel U270 w/ISC Engine (which I bought new in late 1999)
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1/19/07 Spoke to Cummins yesterday, if the pump fails and you are still covered by warranty, they will perform repairs at no charge. TWI