old 300

I have been wondering about the new fuel and decided to e-mail Cummins. I asked the question about what the reduction in the sulfur was going to do to our engines and related parts. This is the e-mail I received from them( Powermaster@cummins.com).

"Summary: ulsd

Solution:
Thanks for your Email message.

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, in the United States, 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 a 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 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.

We thank you for your interest in Cummins products." End of e-mail..


I hope this information helps us understand this matter, I will continue to use the Stanadyne P.F. that I have been using and am wondering about the use of 2-cycle oil that I have been reading about on these forums.

Geico266

Good Post

There will be alot of voodoo out there about the new diesel. Good to see straight info.

Hipshot

I ain't buying it! I just bought my 1st tank of ULSD. I ave 21 mpg normally. Since the moment I fueled up I haven't been able to break 18 mpg on the way to work!!!! Waht changed?

THE FUEL OF COURSE!!!! And we won't even DISCUSS the price!! REVOLT!!!!!!

XLR8R

The wind? Your driving habits? Traffic? Winter fuel? Maintenance issue? Miscalculation? A loaded bed? Did ya see a trailer tailgating you?

Did you be any chance already have an expectation of reduced fuel economy due to ULSD?

MikeyB

I lost about 2 mpg for the last two months since ULSD was introduced in this area.

Kemble

Maybe some of you guys noticing big MPG losses are starting to get shipments of winter fuel?

For what its worth, the fuel filter guy said he was still getting about the same mileage.

XLR8R

Kemble - I liked your post before you edited it, too

Kemble

Yeah, it was good but figured some people might take offense, thought i would make it more user friendly .

XLR8R

Yes, you have become wise in the ways of the Thread, young Kemble...

Kemble

Just tryin' not to step on any toes .

MikeyB

Hardly ever see winter fuel down here..

MikeyB

Hipshot

Nah I'm pretty methodic about this kind of stuff. I've been using my scanguage for about a year now. Working in an engineering dept ya tend to understand variables. That 21 mpg figure is an average under the current conditions & driving habits. I expected a small variance with the current weather changing a little cooler, but adding the possibility that winter fuel hit at the same moment... well it just seems pretty coincidental. I'll give it a little more time and we'll see if the average improves.. But I've been driving on this stuff a week now. And it's pretty clear there is a marked change in my mileage. Even on my best behavior, I can't seem to get close to my average. I put the winter grill on last night, We'll see if that improves things...