DEF usage
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
Sam
Senior User
Joined: Apr 2010
Posts: 303
Likes: 0
From: SE Wisconsin
What the nay-sayers seem to miss is that whether the DEF is 3 cents a mile or 3 miles a cent, the lower EGR that it allows should contribute to better diesel fuel economy - which is one of the reasons why almost all diesel builders have chosen DEF. Diesel plus DEF should cost less per mile than diesel plus lots of EGR.
Post Fiend
Joined: Apr 2004
Posts: 5,158
Likes: 35
From: North of Salt Lake City
What the nay-sayers seem to miss is that whether the DEF is 3 cents a mile or 3 miles a cent, the lower EGR that it allows should contribute to better diesel fuel economy - which is one of the reasons why almost all diesel builders have chosen DEF. Diesel plus DEF should cost less per mile than diesel plus lots of EGR.
Post Fiend
Joined: Jan 2009
Posts: 6,521
Likes: 11
From: Greenwood, SC
Sorry about my math, I throw a dinger out there now and then.
At any rate, cost per mile is really low compared to tires and fuel.
And, MPG is supposed to be better (thanks kluger) so the cost should offset/cancel each other when compared to other modern diesels (don't argue the 7.3!)
At any rate, cost per mile is really low compared to tires and fuel.
And, MPG is supposed to be better (thanks kluger) so the cost should offset/cancel each other when compared to other modern diesels (don't argue the 7.3!)
Post Fiend
Joined: Apr 2004
Posts: 5,158
Likes: 35
From: North of Salt Lake City
Let me go out on a limb here and say that 5% of the total 18% improvement in mileage is due solely to DEF usage. Here's the math: a 5% improvement in mileage of a 2010 Super Duty that averaged say, 12 mpg means that the 2011 will now get 12.6 mpg. Over a 25,000 mile period assuming $3/gallon fuel the savings is 99 gallons or $297. Assuming DEF at $3/gallon you would spend $75. If those assumptions are correct, DEF saves $222/year. If DEF costs $10/gallon (which is crazy), you save $47 per year.
Regardless of the dollar cost/value of DEF, there are other benefits beyond the reduced EGR maintenance cost. Clearly there are environmental and health benefits as well. Bottom line, you're making money by using DEF (not much, but a little) and being a good citizen to others and mother earth as well.
Senior User
Joined: Apr 2010
Posts: 303
Likes: 0
From: SE Wisconsin
Epic - thanks for mentioning the environmental benefits. As much as I love the roar of a well-tuned engine & the smell of diesel in the morning the fact that we can have horsepower & torque aplenty while still leaving things a little cleaner for our kids appeals to me. Does that mean I'm getting old? 
Posting Guru
Joined: Jun 2006
Posts: 2,096
Likes: 0
Isn't promoting the environmental benefits of DEF a bit like promoting plug in electric vehicles without considering how the electricity was generated?
Like electricity, DEF doesn't just happen, it has to be produced, packaged and distributed.
Like electricity, DEF doesn't just happen, it has to be produced, packaged and distributed.
Post Fiend
Joined: Apr 2004
Posts: 5,158
Likes: 35
From: North of Salt Lake City
Not to mention the energy and materials used to develop the DEF injection system installed on vehicles. DEF systems didn't just appear off the shelf. There was a cost to that when we bought the trucks. I'm sure Obama and the EPA thought all that through and decided it was worth it... (sarcasm) They know best you know... (double sarcasm)
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Apr 2010
Posts: 303
Likes: 0
From: SE Wisconsin
I think I'll go have a beer and make some of my own.
Cheers
Senior User
Joined: Apr 2010
Posts: 303
Likes: 0
From: SE Wisconsin
There isn't much to DEF - urea & de-ionized water. There's no additive package like in lubricating or fuel oils. Anything that meets the SAE requirements (and thus carries the SAE logo) should be pretty much the same. Plus its not going to go through the engine, only the SCR catalyst and the DPF.
What we do need to watch out for are storage tempertures. Time spent above 85F begins to reduce its 18 month storage life. Below 11F and it will start to freeze - that's why the truck uses exhaust heat to warm it up if it's cold out before it will start injecting it. If the urea starts to crystalize (freeze) it will plug the injector.
As has been mentioned, its been in use in europe, they call it AdBlue, for a few years and I'm not aware of any major problems with it there. Stick with a name brand, buy from a place that turns their inventory and if you do want to keep a jug or two around home, don't leave it outside. Since the computer gives plenty of warning before you run out, ~800 miles I think, I'll probably just purchase it as needed. I don't expect it to be a big deal.
What we do need to watch out for are storage tempertures. Time spent above 85F begins to reduce its 18 month storage life. Below 11F and it will start to freeze - that's why the truck uses exhaust heat to warm it up if it's cold out before it will start injecting it. If the urea starts to crystalize (freeze) it will plug the injector.
As has been mentioned, its been in use in europe, they call it AdBlue, for a few years and I'm not aware of any major problems with it there. Stick with a name brand, buy from a place that turns their inventory and if you do want to keep a jug or two around home, don't leave it outside. Since the computer gives plenty of warning before you run out, ~800 miles I think, I'll probably just purchase it as needed. I don't expect it to be a big deal.
Thread
Thread Starter
Forum
Replies
Last Post
Icthus in AK
6.7L Power Stroke Diesel
26
Aug 14, 2015 10:41 AM
