DEF Additive

[trn the page]

Will someone tell me about how long this DEF stuff will last or how many miles??

[traveldawg]

It looks like you're a Tiffin owner. Assuming you have a Freightliner then figure 2% of fuel usage (i.e. 2 gal of DEF per 100 gallons of fuel).

[SW4UA]

I think our rig has a 12 or 13 gal tank, so it will last a long time. Noticed the flying J's around Birmingham are starting work to put in DEF pumps at the truck fuel areas. Will make it a lot easier to keep the tank full.

[Cruzer]

It also has a shelf life. DEF can be stored at temps from 23F to 86F for up to one year. It's prudent to keep a few jugs on hand as spares but don't stock up too much on the stuff or it may not be goodby the time you use it. Rotate your stock and don't load up before winter storage. If you store it in a hot location it'll degrade fast so try not to exceed 86 degrees.

[MNRVr]

Does anyone on the forum know what properties urea provides to the the process that reduces pollution output on the diesel engine?

[powderman]

How does it work??? http://www.fleetguard.com/pdfs/produ...es/MB10033.pdf

[JMonroe]

Cummins estimated the 2% DEF to fuel ratio and so far I've found that to be fairly acurate. If anything, my use has been just under that (total of 4600 miles on the rig to date). Our DEF guage will drop from full to 3/4s in just over 1,000 miles of travel so that suggests a total range, for our DEF tank, of over 4,000 miles.

I've got a related question - how many of you using DEF have seen it sold bulk where you buy fuel, and how much is it per gallon? I'm buying it in the 2.5 gallon containers at $12 a pop (about $4.80 per gallon - adds less than 10 cents to the cost of a gallon of fuel, for our rig [about 2.5%], but according to Cummins is providing an average of 5 or 6% better fuel economy than the '07 emissions compliant engines).

[Ann n Gene]

I dont know much of anything but just got a new coach that requires DEF. ONE, does anyone know if farm liquid fertilizer grade urea (32% urea in water) meets ALL the specifications of Cummins. It IS within specs for urea (31.5% +or-1.5%) but I do not want to take a chance unless I KNOW it meets the Cummins specs, but it is a lot cheaper. I have seen it in stores for as high as $12.95 per gallon. Only have 2000 miles on my new coach but the DEF guage is still on the full mark, hope it is working, guess I will pull the cap and measure it tomorrow. Whole new ballgame, guess we will just have to learn the rules. lol

[MNRVr]

Thanks for the replies.

[Idleup]

The day I have to screw with a DEF tank is the day I'll go back to gas engines - this is a rip off to the rv industry - RVs should be except from this BS.

[JMonroe]

Quote:

Originally Posted by Idleup The day I have to screw with a DEF tank is the day I'll go back to gas engines - this is a rip off to the rv industry - RVs should be except from this BS.

You're certainly not alone in your feelings on the matter, but the DEF system is simply an alternative to meeting exhaust emissions standards imposed by congress and the EPA. In doing research prior to buying ours, I learned that the DEF engines tend to be a bit smaller, for a given power output, and a bit more efficient because of that. As of right now I don't think there is an alternative to DEF for the larger rigs, although there reportedly will be soon. Strictly by the numbers, there are far more DEF engines being sold than the EGR variety, though much of that is simply a function of the production capability and popularity of the major players (including Ford and GM).

I've never owned a diesel before, but I've sure gotten stuck behind my share on the highway, or at a stoplight. I can tell you that there is not the slightest hint of diesel smell coming out the tailpipe of our coach. (Not true of our Aqua Hot or gen set.) What you will 'smell' I'd describe as a 'wet' smell, nothing offensive at all. As for adding the DEF, when needed, its about as simple as adding window washer fluid (albeit much more frequently) and I'm hearing that more and more fuel stops are putting in bulk tanks/pumps making it even easier.

All things being equal, would I choose to have the DEF tank? No, but it's a very minor irritant, at most, and in my opinion.

[Idleup]

Bottom line as few miles as Owners put on personal RV's and boats, they should be except from this BS requirements. Aside from geting screwed at the pump with diesel prices now we have to pay more and screw with that when we fuel up. Sorry this is totally out of hand now!

[openpro]

I was worried about dealing with the DEF stuff but now that I have it I'm really pleased. It's not a big deal to keep the tank full but there is ZERO diesel smoke.

[Midniteoyl]

Another reason not to buy diesel....