New low-Sulphur Diesel Fuel--Impact on older Diesel Engines

[Uncle Ben]

Greetings,

I am a new member who is contemplating purchase of a 1998 Dynasty Diesel Pusher Motorhome 40 ft (Approx). It has a Cummins Mill (I don't know the displacement).

I have read the 2007 Cat report on the main page and its author's concern about the new Diesel Fuel that is now standard at all Gas outlets selling Diesel. (He found out the new engine ran great on the reformulated Diesel and got, for his 18-wheeler rig, great gas mileage.)

My question is regarding the impact that the new formulated Diesel would have on the 1998 Cummins engine. Could I expect the same mpg mileage irrespective of the type of Diesel used, worse mpg, or better mpg?

A prompt response will be greatly appreciated.

[Uncle Ben]

Greetings,

I am a new member who is contemplating purchase of a 1998 Dynasty Diesel Pusher Motorhome 40 ft (Approx). It has a Cummins Mill (I don't know the displacement).

I have read the 2007 Cat report on the main page and its author's concern about the new Diesel Fuel that is now standard at all Gas outlets selling Diesel. (He found out the new engine ran great on the reformulated Diesel and got, for his 18-wheeler rig, great gas mileage.)

My question is regarding the impact that the new formulated Diesel would have on the 1998 Cummins engine. Could I expect the same mpg mileage irrespective of the type of Diesel used, worse mpg, or better mpg?

A prompt response will be greatly appreciated.

[Norm Payne]

I have found the new ULSD fuel to be a non-issue. There are some fuel stations still pumping LSD, but neither you or your diesel engine will notice any difference in the type of fuel you use.

[skp_member]

Norm, You beat me to it.

My '96 CAT does not know the difference. Same milage on both.

Uncle Ben, Your '98 M Cummins will do fine on it.

Jim
'96 Safari 3540, 300 CAT, 520W Solar

[Route 66]

Uncle Ben, welcome to iRV2.

I agree with the other posters that using ULSD is not an issue.

[Pusherman]

The literature on ULSD states that you may get about 1-2% less mileage due to energy content in the fuel. Negligible.

I've had my CAT C-7 for a year now, and I have had no issues with ULSD. I doubt you will see a difference in mileage.

[John66]

On the Country Coach users Yahoo group, a lot of people are reporting that the USLD in pre 2008 Cummins engines in their coaches are shrinking, leading to leaks. Most common seems to be in the fuel pump.

[Norm Payne]

I belong to several RV groups and when ULSD first came out there were a few reports of leaking lift pumps in Cummins engines. But in the last few months I have not read of one failure. Could it be the lift pumps were ready to fail anyway and ULSD got the blame.

I talked to a Cummins engineer and he said Cummins engines from 2005 and newer have a different lift pump with better seals than older Cummins and will not fail.

I had service done at Cummins in Albany, GA and I asked the service manager if they were seeing any failures from ULSD and he said they had not seen any problems. A couple of months ago I talked to the service manager at Cummins Coach Care in Clarksville, IN. He said they had not had the first leaking problem or failure due to ULSD and I believe him. He is a good guy and I have known him five years.

This is why I say I think ULSD fuel is a non-issue. As Pusherman stated above, the oil companies report engines will get 1-2% lower fuel economy which is too low to measure unless you have a way to count BTUs in a gallon of diesel.