Diesel Fuel Additive

[meandmyprs]

I was chatting it up with someone (Detroit Mechanic) the other day about the bus and he asked me what kind of fuel additive I was using. I am using none. Should I be using some?

Brent

[Gary & Peggy Stevens]

Last time I had my bus @ Stewart & Stevenson, I asked them the same question... about additives for fuel and or oil?

DD does not recommend putting in any additives, in the fuel or the oil. If you use good quality oil that is the only lubricant you need in the crankcase, with the exception of possibly winterizing your coach for a long winter. That is a different story.

Gary S.

[tdelorme]

I think the jury is still out on the Ultra Low Sulphur Diesel we're using these days. I know Cummins has had some lift pump failures related to low sulphur diesel. I have started putting about fifty gallons of diesel out of the farm tank in the coach every so often. It smokes just a little bit more than normal but it is real good stuff. I have an open quart of transmission fluid in a bay to explain the faint red color of the fuel if I ever get checked and a stack of seven and eight hundred dollar recepts for fill ups as backup. If I did not have access to high sulphur diesel, I think I would add a bottle of Howes Diesel Treatment every other fill up.

[garyde]

I had my Coach Lubed and the oil changed up in Oregon and the mechanic asked me what kind of additive I wanted for the Oil. Having never been asked this before, I said none. The Fuel additive, I am always seeing bottles of fuel additive at the check out stand at Pilot and Flying J. I really have no idea whether to use any of these.

[merle&louise]

I have always felt that "fuel additives" are just snake oil. I have had diesel boats and RVs since 1981, and I have never used a fuel additive. No problems so far. I will say that I use my toys a great deal. They just don't sit without be run for months at a time. I start and run my engine/generator minimum once a week. Maybe that's why I haven't had any problems. Some people swear by them, so I guess it is up to the individual.

[Joe Cannarozzi]

In warmer weather I'll never use it but when the temp drops below 20 or so for a prolonged period I will use about triple what is suggested and 10 or 20 gal of kerosene on a full tank to boot.

Merle brings up a good question. Are our pickups a tube comming down from the top stopping just short of the bottom or is there a hole at the very bottom.

The first way sucks it allows smutz to accumulate and may require periodic bottom draining. If it is drawing directly off the lowest point that is good.

[dalej]

I thought Bill told us that Prevost designed the tank so there is around 30 gallons of fuel always at the bottom. This keeps the tube from sucking air while the fuel is moving around while driving.

[Joe Cannarozzi]

Great. Water goes to the bottom along with particulate matter. So what good is a fuel and water separator if water is allowed to lay in the bottom of the tank below the pickup.

[Jon Wehrenberg]

I doubt if we drag around 30 gallons of fuel we cannot access. If our tank capacity is XXX gallons, we can only fill it to a percentage of that value because of the need to have some space for fuel expansion.

I can't remember what the percentage of unusable head space in my tank is, but I know I don't have 298 gallons of fuel available even though that is my listed capacity. If I can only fill it to 90% of its rated capacity I really only have about 270 gallons on board and probably have 10 of those still in the bottom of the tank when the fuel pickup starts sucking air.

As to water and crud sitting in the bottom, I am sure when the coach is parked gravity puts water and solids at the bottom, but as the coach is driven that stuff is disturbed and does enter the fuel pickup where it is trapped by our fuel filters. I suspect most of us have very clean fuel tanks as a result.