Diesel and DEF???

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Nov 5, 2007
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I had a Ram 1500 truck, and it was plenty nice, but my wife’s company gets a fairly hefty discount on Ram, Jeep and Dodge vehicles.

Back in April we ordered a new truck, another Ram 1500. This time diesel. I’ve had a few diesels in the past and my parents have also.

But this truck is the first to have a DEF filler and gauge. What the heck is DEF? I know it stands for Diesel exhaust fluid. But what is it for?

I also can’t figure out how long it lasts. To be honest, I also haven’t read the manual yet either. But online, some people claim 10,000 miles, others say around every 3 to 5 tanks of diesel.

Apparently you can buy it at Wal-Mart?

And man, is this truck nice. No more waiting for the glo plugs to warm up. Just press the ignition button and it starts right up. But it’s got air-ride suspension, heads up display, 19 speakers in the stereo, adaptive cruise control, lane keeping assistant, etc. And a very nice and quiet ride.
 
DEF is injected into the post-combustion gasses to cut down on certain emissions. Think of it like a catalytic converter for a diesel engine, with a catalyst that does not regenerate and thus needs to be constantly replaced.

I'd sure hope a fancy new diesel vehicle would have a sensor that tells you when the DEF is low. The fluid just needs to be added when it gets low. Consumption is more or less proportional to fuel consumption.
 
It does have a DEF sensor and DEF gauge like a fuel gauge. Between my parents and myself, we’ve had 5 diesel cars and trucks I’ve driven extensively, and none of them have had this setup.
 
One reason for getting a new truck is gas mileage. I was so tired of the 15 mpg (on the highway and in town) with the last one. This one with diesel should get almost double that on the interstate.

Here is the truck:

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Not porportional to miles driven , but porportional to idling and light throttle driving .

DEF is available at Wallys , most auto parts stores, and better stations that sell diesel . Fleets have it in bulk , either in 55 gal drums , or pumps .
 
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Thank you for all this information. The last diesel I had was a 2013 VW, and now we know they didn’t care about emissions with those cars. :)
 
My mechanic said that DEF has a “shelf life,” at least once it’s been put into your DEF tank. No idea if he’s correct, nor does it really matter to me- it’s easy to follow his advice.

His advice was this: run your DEF way down, before refilling it. In other words, don’t go “topping it off” with every fill…

I like to fill it at the pump, at a truck stop. That way you can fill it w/o trying to figure out what size jug to get, or dispose of the jug.
 
Read through the trucks manual, it should explain everything, Ram likely has you tube videos as ford does showing how to refill it and about how many miles before you need to refill. When it dries out it crystallizes. So, if you spill any on the truck paint or splash and on the ground and your shoes. You get spots on that stuff. It will wash off. Store bought stuff is normally 2.5 gals. It does have a shelf life, I don't recall how long. Don't care, I use it up. I fill at a station to get only what I need which is around 4 gals at a time. DEF has a high percentage of water in it which gives it a freeze point not far under 32F. Your DEF tank should have a heater so using it is not the problem. The problem is the tank is plastic and if it freezes while parked, a full tank could cause a cracked def tank. I keep mine about half full in winter, not topped off unless on a long drive.
 
Complain all you want, DEF does reduce reduce NoX emissions. NoX is one component of good old Smog. Folks complain about things like catalytic converters and smog controls on vehicles. But these in combination with reduced emissions from stationary sources has made an amazing improvement in the air in SoCal. Our worst "smoggy" days now are significantly better than a good day when I was a kid.

Diesel engines were the last type of engine to be "smog controlled". But they did release a fair amount of pollutants. One of the biggies was particulates. You know that black smoke from the exhaust pipes on trucks of truckin' songs.
 
IMO, unless you're pulling a big load or driving a smaller vehicle, Diesels are a false economy.

The EPA further regulating them has killed any advantage they had in economy. If that wasn't enough, diesel prices that were traditionally cheaper than gas have exceeded the price of gas.

My take is, unless you're willing to wrench & maintain 20-30 year old vehicles, you are at the mercy of the government, their ties with the oil industry.

This could be off topic , but the bottom line is my opinion on diesels & how they were once winning, but winning so well that the EPA saw a ripe opportunity to step in, & ruined it all.


4 cyl. diesel Toyotas used all over the world for several reasons. Cannot comply here. A shame
 
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I work at a Dodge dealership, those engines are trouble free in the trucks. Depending on your driving style you won’t be spending much on DEF, on average you’ll use a gallon of DEF for every 50 gallons of diesel you burn. Talk to your dealer about a service contract as oil changes are expensive on those. I recommend a fuel filter at least every other oil change.
 
I bot a Ram 2500 Diesel new in ‘15. Aint had minutes trouble out of it, and for some reason I dont use as much DEF as most?? But still will prob hav it deleted
 
I hear all the problems that turn up when using DEF-dizzles in cold weather. Psuedo-Son works for HyVee foods which runs OTR trucks thousands of miles daily and his Son is a shop manager for a JD dealership. The horror stories are numerous, long, and painful.
One of the main reasons the older tractors have nearly doubled in price is because so many users don't want to fight DEF-dizzles through the winter.
 
" I recommend a fuel filter at least every other oil change."
REALLY??????? That would equate to something like 200 hours of engine time. Good Grief, that's terrible. Our farm tractors get fuel filter changes at maybe 1000 hours or once a decade if we think it's necessary.
 
I have a 2017 Ford 6.7 Powerstroke. I haven't specifically tracked the DEF usage but in my case it averages one 7 gallon tank of DEF for each oil change - in my case that's right around 7000 miles.

*NOTE*: You shouldn't run your DEF tank empty. I haven't tested the theory on my truck - but the computer will shut you down no matter where you are. I personally know two different people which this has happened to. They got a warning first - 'you have x-miles to go' - they ignored it and the truck speed was eventually limited - by that time there was no DEF within range and the computer shut their truck down on the interstate.

Oops.
 
After much analyzing on it before declining the diesel option, thoroughly agree with post 13. It is spot on.

DEF was a response to problems caused by new exhaust regs implemented prior to DEF. In other words, it was brought in to "correct" mechanical problems caused by prior changes to exhaust regs. It has its own litany of issues and problems. Yes, it "works".....when it works. Nuff said, for me.

The Feds/EPA don't want you driving a diesel. So, they are going to regulate it to the point where you say "whoa, this is crazy, I'll buy an EV". It's pretty much there now, but we just continue to ride our economic sugar high and carry on as normal.

Enjoy your new truck, however!
 
Ford, at least mine a 2013 f350 6.7 engine manual says the same about fuel filters and it uses 2. My opinion is only that; the fuel filter replacement is so often to help save off fuel system problems that cost thousands if the fuel pump, rail, injectors get water into them. In my truck the fuel filters change is in the 20,000 miles mark. Here's the thing thou, I purchased mine used with 60,000 miles and 3 years old. I changed the fuel filters to have a base to go on for replacement. They have date stamps on them. Mine were date stamped before the truck came out of the factory. So, I question were they ever changed? Car Fax showed only oil changes done on it. Some people open the release valve on the 1st filter on a routine cycle to check for water and debris. Another way to save the engine from damage and takes a few minutes. My truck is now at 110,000 and never has had any problems engine wise. I am on the 3rd or 4 set of filters, not sure unless I go and look at the record. I paid about 125 last time for ford filters. Takes 15 mins to change them. If that breaks someone's bank account for owning a newer diesel then don't buy one.
 
As with everything else, the more technical and efficient something gets, the more problematic it becomes and the attention it requires.
I no longer own a diesel pickup for two reasons: 1:cost of ownership/operation 2:much too technical for me to pay the $$ noted in #1.
 
Look at what it's made out of and then be really confused.....

Russians are laughing at us... it contains their urine.
DEF does have urea in it. But, there are two types. That which Blume is thinking of and an inorganic form The inorganic form comes from combining various raw materials. It’s been around for about century and is used in a number of products.

No urinating Russians are forced to pee to produce DEF.
 
DEF does have urea in it. But, there are two types. That which Blume is thinking of and an inorganic form The inorganic form comes from combining various raw materials. It’s been around for about century and is used in a number of products.

No urinating Russians are forced to pee to produce DEF.
It's still funny.
 
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"I read once that the democrat party gets 100% of the profits from the sale of DEF.
Agree that it is a scam.
Also destined for shortages it seems.
Truck won't run without it."
From what I hear, Jimmy Buffet is the big name in DEF. How much he passes on to the Dems can't be confirmed.
It's already a shortage--one entity controls most of the DEF imported AND 100% controls the offloading at the ports. (see above)
Control shipping/transportation and you control the majority of America (as we know it today).
Some(and the number is dwindling) diesel vehicles can be DEF deleted. Fewer and fewer left running. I used to have a diesel pickup that didn't even need a battery to run during daylight(as long as you left it parked on a hill).
 
Some(and the number is dwindling) diesel vehicles can be DEF deleted.

Our local enforcement folks have figured out what a gold mine this is. They've been poppin the modders here with some hefty tickets. EPA enforcement has already put most of tuners and shops doing that work out of business. Yet to be seen if they'll take customer lists and pursue individual enforcement.

I'd not modify a modern diesel myself. Fines just not worth it.
 
My 1989 F-250 with an International Harvester 7.3 IDI engine has none of that crap... IF she doesnt bust off first thing in the morning, a touch of ether will help.........has never left me stranded , and still runs good.
Keep your electronic injection, you can have it.
 
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Diesel Exhaust Fluid (DEF) is a non-hazardous solution, which is 32.5% urea and 67.5% de-ionized water.
Urea: A colorless crystalline compound which is the main nitrogenous breakdown product of protein metabolism in mammals and is excreted in urine.
In another thread it was mentioned, don't know if it is true, that most of the urea comes from plants in Russia...
 

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