I have a 400 hp C9.  I tried Lucas deisel additive for a 2000 mile trip and found at least a .8 mpg improvement on my 39 foot 08 contessa.  Has anyone tried this?  The truckers use thise stuff all the time.  I think its Ok on the 400 but not the 425 C9.  Is there any damage one could do by using this???
Thanks
Jerry Leonard

Why NOT the C9 425 hp?

From the research that I have done on diesel fuel additives there are several reasons to use them. It can be used as a biocide, water in fuel control, a stabilizer, a lubricity improver, an injector cleaner, an antigel, or a cetane improver.

The diesel fuel additive that you chose, if you use one, depends on what you are trying to accomplish with the additive. If you are using an additive for fuel economy improvement only, there is no clear cut answer.

Most of the independent studies that I have read indicate that an additive that is designed as a cetane and lubricity improver, and an injector cleaner, will improve your fuel economy. Although the economics of using an additive usually works out to the amount money that is saved on fuel is offset by the cost of the additive.

So you probably will not save money on your fuel budget, but there are other benefits that vary by the properties of the fuel that you are using.

As for as using an additive in a 400 HP C9, but not a 425 HP C9, there is no technical evidence to back up that viewpoint that I have ever seen.            

Gerald

Hi Gerald.  As youre the GO TO guy on this, perhaps you will know.  In our 300 or 330 hp CAT, would the occasional use of a cleaner base product work like a gas engine injector cleaner.  We only have 75K miles but at 12 years old it might be smart to use this additive to give her a cleanup?
Thanks

I am not sure about the 425 C9...CAT told me its a very different set up but probably has nothing to do with additives.
Jerry

http://ohe.cat.com/cda/files/380705/7/ULSD%20-%20FAQs,%20Cat,%20April%203,%202007.pdf This is the link to CAT on highway engine FAQ and ULSD and they have an answer in reference to fuel additives.

Keith,
There is a lot of similarity between a gas engine injector cleaner and a diesel injector cleaner, although a clogged injector on a gas engine is much more common than one on a diesel, mostly due to the much higher pressures at a diesel injector.

The idea of running a couple of tanks a year with an additive has some merits. The benefits will vary by the engine condition and the fuel that you are using, but there is at least a 50% chance or better that you will pay for the additive with the fuel savings if you use an additive with a cleaning agent and a cetane booster.

The additives that are targeted as a biocide, water control, or antigel will probably be of no benefit to you if you do not have those specific problems. A lot of 18 wheel trucks run an antigel additive all winter because they operate in below 0 weather at times and they get restricted fuel filters without it.

I do not know about you, but I head south a long time before it gets that cold.

Gerald

The additive discussion is on page 6, item 14 of Richard's post of 5/3/10.

Larry

The guys at Bend Service Center told me years ago not to worry too much about it, because fuels sold in colder or wetter areas already have the necessary additives in them.  The trick is to not fill up in a warm dry region (that may not have additives in the fuel) and then drive to and operate and store in the opposite environment.

Where we live in Oregon it's theoretically not a problem, mainly because it would be impossible for us to come home all the way from a summer in the midwest, for example, and not refuel somewhere enroute with additive-included diesel.  Plus, I always fill the tank nearby before parking the coach at home after a trip, reducing moisture condensation in the tank, and additives are included.