# Diesel question



## Dewey (Feb 1, 2010)

I looked for a Diesel section to post this and I didn't see it ,,, My question is... I was at a garage today and we were talking about trucks and such and the mechanic started telling me that all newer Diesels were being built with a Urea Tank. I had never heard of it.. I did a quick search online to see for myself and the site I went to did in fact confirm what he said...And from what I saw it is on all Diesels built after January 2010 there is supposed to be a Urea tank in conjunction with a fuel tank ...My question is how many guys on here have a truck with this system... is it in fact on all Diesels ??? I have never seen Urea at a fuel station is it something only dealers have...?? How expensive is it and does it help with fuel millege ?


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## NICHOLS LANDSCA (Sep 15, 2007)

Dewey;1268400 said:


> I looked for a Diesel section to post this and I didn't see it ,,, My question is... I was at a garage today and we were talking about trucks and such and the mechanic started telling me that all newer Diesels were being built with a Urea Tank. I had never heard of it.. I did a quick search online to see for myself and the site I went to did in fact confirm what he said...And from what I saw it is on all Diesels built after January 2010 there is supposed to be a Urea tank in conjunction with a fuel tank ...My question is how many guys on here have a truck with this system... is it in fact on all Diesels ??? I have never seen Urea at a fuel station is it something only dealers have...?? How expensive is it and does it help with fuel millege ?


Yes they all have it, I'm sure all truck stops have it by now, most gas stations have it. Not sure on price, and no it doesn't help mpg


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## jhenderson9196 (Nov 14, 2010)

They DON'T all have it. Dodge 2500 and 3500 series get by without.


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## CGM Inc. (Dec 15, 2008)

jhenderson9196;1268539 said:


> They DON'T all have it. Dodge 2500 and 3500 series get by without.


X2 on that! Cumins is the only diesel at this point without Urea to pass emissions.


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## 2COR517 (Oct 23, 2008)

Commonly referred to as DEF - Diesel Exhaust Fluid. Getting easier to find, AutoZone carries it.


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## ProSeasons (Nov 30, 2000)

Flying J has it for around $13.99 for a 2.5 gallon sized jug. Brand name 'Blue'

http://bluedef.com/product.html

Keep the tank full until you need to pass inspection, then turn the system on. Down the road, turn it back off. No problem.


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## jhenderson9196 (Nov 14, 2010)

There is no on or off for def. If the tank runs out the truck goes into limp mode.


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## cretebaby (Aug 23, 2008)

jhenderson9196;1268539 said:


> They DON'T all have it. Dodge 2500 and 3500 series get by without.


The cab and chassis have it.


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## NICHOLS LANDSCA (Sep 15, 2007)

cretebaby;1268646 said:


> The cab and chassis have it.


I thought so, but I wasn't going to start a fight


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## justme- (Dec 28, 2004)

All diesels will have it going forward if they require it to meet the emissions standards, which are based on the emissions of the engine and the class of the truck. The DEF is supposed to replace the DPF system since it will not be able to be defeated by the end user as most DPF systems are being done, and the fluid will not affect mileage like the DPF system does.
You can thank all the diesel "bombers" who think blowing black smoke (unburned fuel) is cool, the cheap company owners running old and worn out class 8&9 trucks, and the greenies for reacting in typical fashion (Eww smoke must be bad for the environment) forcing Congress to tighten the emissions on these engines.
Also, Cab Chassis trucks are under the definition of commercial truck where the same truck with a pickup bed from the factory is not - a minor difference which has a major impact on the emissions classification for the vehicle.


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## Dewey (Feb 1, 2010)

I guess its one more reason to buy a gasser next :salute:


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## wewille (Jan 20, 2009)

According to ford, they claim using the scr system with urea has allowed them to improve fuel economy significantly over previous exhaust treatment systems which only used oxidation catalyst and a dpf and regeneration, Ford claims it does not need to go into regen nearly as much(which kills fuel economy). Ford says their cost of operating is less over a years time than is the dodge with a cummins that does not use an scr. I believe cummins has found a way to use enhanced egr and a more aggressive regeneration process to reduce NOX levels. The aggressive regen that Cummins is using has not allowed them to improve fuel economy nearly as much as ford and chevy. SCR is selective catylist reduction, it is the name for the process where they inject the urea to reduce NOX emissions. Very fascinating stuff. But I agree, gassers are far more economical now days.


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## wewille (Jan 20, 2009)

justme-;1268752 said:


> All diesels will have it going forward if they require it to meet the emissions standards, which are based on the emissions of the engine and the class of the truck. The DEF is supposed to replace the DPF system since it will not be able to be defeated by the end user as most DPF systems are being done, and the fluid will not affect mileage like the DPF system does.
> You can thank all the diesel "bombers" who think blowing black smoke (unburned fuel) is cool, the cheap company owners running old and worn out class 8&9 trucks, and the greenies for reacting in typical fashion (Eww smoke must be bad for the environment) forcing Congress to tighten the emissions on these engines.
> Also, Cab Chassis trucks are under the definition of commercial truck where the same truck with a pickup bed from the factory is not - a minor difference which has a major impact on the emissions classification for the vehicle.


Just to clarify, the new scr systems which use def are NOT eliminating the dpf systems. Ford and chevy use both.


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## wewille (Jan 20, 2009)

NICHOLS LANDSCA;1268425 said:


> Yes they all have it, I'm sure all truck stops have it by now, most gas stations have it. Not sure on price, and no it doesn't help mpg


It indirectly helps boost fuel economy, by reducing regeneration events among other things.


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## JDiepstra (Sep 15, 2008)

Best bet is to buy the lowest mileage pre 07.5 diesel you can find! Cummins, of course!


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## justme- (Dec 28, 2004)

Actually, best bet is buy the condition 94-97 Dodge you can get- no computer controlled engine, no expensive injectors, no glow plugs, no block casting issues (53 block), no DEF, no DPF, no EGR, (only a handful of trucks had CATs), and can easily put out the power of today's diesel's with a few tweeks.
If you can keep the body from rusting away and put a good transmission in it you're set.

Thanks for the correction, I assumed Ford and GM would be doing away with the DPF since Cummins is with the Urea system, especially since the DPF/CAT is where a large portion of mileage and driveability issues come from.


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## LunchBox (Oct 28, 2010)

Let me know when there is a by pass for this. Don't even get me started on how diesel burns cleaner than gasoline


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## BossPlow2010 (Sep 29, 2010)

Dewey;1268787 said:


> I guess its one more reason to buy a gasser next :salute:


They're plenty more reason to buy a diesel over buying a gas.
Eg. Better fuel economy.


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## 2COR517 (Oct 23, 2008)

BossPlow2010;1280391 said:


> They're plenty more reason to buy a diesel over buying a gas.
> Eg. Better fuel economy.


You better be driving lots of miles hauling lots of weight. And keep the truck for a long time.


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## BlizzardBeater (Aug 29, 2010)

It also likes to freeze in cold temps, like during a snow storm.


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## Turf Guy (Feb 5, 2011)

Just picked up my new 2011 Ram 2500, no DEF as of now!!! The dealer says they don't know how much longer cummings will get away with it though! Have it on a Ag tractor, and yes it does like to freeze up in sub zero temps.... The DEF is expensive as well!!! 250gal tote, 699.00!!!!tymusic


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## NICHOLS LANDSCA (Sep 15, 2007)

Turf Guy;1280554 said:


> Just picked up my new 2011 Ram 2500, no DEF as of now!!! The dealer says they don't know how much longer cummings will get away with it though! Have it on a Ag tractor, and yes it does like to freeze up in sub zero temps.... The DEF is expensive as well!!! 250gal tote, 699.00!!!!tymusic


Ya I heard the CumminGs don't need it, but some of the Cummins do


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## 2COR517 (Oct 23, 2008)

Huh huh, Cummings


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## tuney443 (Jun 25, 2006)

NICHOLS LANDSCA;1280559 said:


> Ya I heard the CumminGs don't need it, but some of the Cummins do


I heard the same thing the other day.Think it was at the local ******* Cummings hangout.Thumbs Up:laughing:


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## tlcjason (Jul 8, 2008)

have 14 Ford 250's all with urea tanks. not a big problem, i buy urea at dealer and fill up every oil change. have had some trucks for 2 years with no problems. like this way better then the ford models a couple years ago, that went in to a cleaning mode and dumped diesel straight into the catalytic converter to keep them clean. Getting better fuel economy and urea is not a big expense.


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## BossPlow2010 (Sep 29, 2010)

BlizzardBeater;1280442 said:


> It also likes to freeze in cold temps, like during a snow storm.


Realy? My Diesel has never froze!
It gels up. And btw it only does this when it's sitting, not when fuel is circulating and the engine is warm.

Edit: I'm sorry I just responded to a old thread, my apologies.


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## Banksy (Aug 31, 2005)

I will not buy a new diesel....period. Too much EPA garbage.


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## durallymax (Nov 2, 2011)

Lots of misinformation in this thread on the SCR system. 

First off SCR is not a replacement for the DPF, they are two different systems with two different objectives. The DPF is for filtering particulates. The SCR system is for reducing NOX emissions. Unrelated to each other however there is a cause and effect that is causing reduced DPF issues thanks to the SCR. But it is due to the fact that the engine can be tuned differently and not because of the actual SCR/Urea. meaning you cant put this on your DPF equipped pre SCR truck and get better fuel economy and fewer issues, thats not how it works. Ill try to breifly explain.

NOX and Particulates are the two main focuses the emissions standards for diesels are trying to reduce. The SOX was reduced by removing the Sulfur from fuel, the other two have to be reduced in the engine itself. The particulates are being reduced by better fuel injections systems and better tuning, with the DPF picking up the rest. The NOX has been reduced by increasing the amount of recirculated exhaust gases, and trying to keep cylinder temps down by reducing compression and retarding timing and thus increasing displacement to re-coop the lost horsepower.

Anybody whos tuned an engine knows cool combustion is not efficient, which is why the diesels fuel efficiency has dropped with every new model in the 21st century. This inefficient burn also creates more particulates, which is why the 07+ trucks have so many issues with the DPF. The DPF is a trap. No matter how the engine is tuned it will catch the particles. The OEMs knew that so they tuned to reduce NOX, and the fuel economy suffered and DPF issues were high. 

Then came the 2010 Emissions. Tier 2 Bin5 technically. The NOX regulations got very strict and OEMs had to look to other options, or just try to increase the EGR and hurt the efficiency even more. Many OEMs implement SCR as the answer to their problems.

So what is SCR? The Selective Catalytic Reduction process was created for the removal/reduction of NOX. It was patented in the 50s and its first commercial installation was in the 70s on a factory. It is used at most power plants and has been outfitted to vehicles in europe for a few years as well. The process involves injection urea into the exhaust stream with the reaction occuring in a catalyst. It converts harmful NOX into safe Water and Hydrogen with a trace amount of CO2. Its a very simple system at its core.

What is the Diesel exhaust fluid? 32.5% Pure Industrial Grade Urea (not the stuff farmers use), and 67.5% de-ionized water. This is what the API standard calls for. The fluid does require special handling. It is mildy corrosive, can irritate your skin and eyes, and will crystallize when spilled. It freezes at 12* Fahrenheit. It should be stored out of sunlight and in a cool place if possible. As temperature increases DEFs shelf life shortens as the heat will degrade its quality due to the normal Nitrogen cycle. It is listed that at constant 86* in a dark place, DEF will last for 2 years. Lower than that it will last longer, above that its life will be shorter, at 140* it will only last 1 week. The temperature fluctuations also effect it, so keep it in your shop or garage if you can and only buy what you need at one time.

It also requires special pumps, a Nylon pump with viton o-rings will work cheaply, the true DEF transfer pumps are $800 and up as they are made out of stainless. And there is a special nozzle with a 19mm spout to fit the def fill. The tanks should never be topped off to allow room for expansion.

All DEF containers are required to have a born on date or Batch code so the end consumer can find out when it was made.

DEF prices range from $2 on up. Dealerships are usually highest, with fuel suppliers being the lowest. I just bought a 330 gallon tote for $2.22 per gallon whereas the price of a 2.5 jug at wal mart is around $5 per gallon. But again, dont get ahead of yourself buying too much.

Im assuming most people on here live in cold conditions and are probably worried about the DEF freezing, dont worry the systems are designed for this. They go into a DEF thaw mode and allow full power while the DEF is thawing. The EPA allows 30 minutes of run time on off road vehicles because the DEF should be thawed by then, if not there is an issue.

Most pieces of equipment have gauges, some (like GM trucks) only have a warning for when the tank is getting low.

If the operator fails to fill the tank, trys to pour anything but DEF in it or pours bad quality DEF in it, the system will sense it and put the vehicle into limp home mode, on GM trucks there are 9 warning stages, essentially they limit you to 55mph and on the final stage limit you to 4mph. Off road equipment cuts horsepower by 60%. 

There is a refractometer you can buy to check the DEF quality.

So what OEMs are all using SCR? For larger commercial trucks, everybody but Navistar, they are using Enhanced EGR, for passenger vehicles, everybody but Dodge on their consumer version of the ram, they are using a NOX catalyst and EGR. For agricultural equipment, CNH,Claas,Agco and some others are all using SCR. Anything with a Deere, Cat and most things with a Cummins, are not using SCR. For construction equipment and such, most OEMs are not at this point due to the infrastructure for supplying and storing DEF in remote areas. but they do say they plan to use it for 2014 which is when the big clamp gets put down.

Deere, CAT and Navistar are the movers and shakers against SCR with Navistar being the most arrogant.

It is important to note that the offroad equipment i refer to is for engines in the 150hp-750hp range. Engines outside of that range have different emissions standards. Which is why you seem OEMs like Claas and Krone going from two engines under 750hp each power their two largest harvesters switching to one big engine.


What are SCRs benefits over other systems? The Big benefit is that the OEM gets to tune the engine like it has no emissions regulations, meaning they can tune for power, performance, reliability and efficiency and let the SCR and DPF clean up after it, although with that clean of an engine particulate wise, the DPF will have much less work to do. You get a cleaner healthier more efficient engine that doesnt have to try to clean itself. Whereas with the other systems the engine is trying to clean itself, its like eating your own feces, why do that when there is a toilet there to clean up after you(SCR).

Fuel economy is generally higher
Oil stays cleaner due to reduced soot, so oil change intervals are higher
Engine life is projected to be longer but that one we dont quite know yet.

What are its downsides? Dealing with the fluid. I love the system but will admit the fluid is the biggest hassle about it. But aside from having to keep it in a stable place with low heat, its no different than filling any other fluid on the vehicle, you already fill your windsheild washer fluid to keep your windsheild clean whats the little extra work to keep your exhaust clean and your pocket full of more money due to less fuel used.

The bottom line is that the systems are hear, and if you want a new vehicle buy your brand of choice. I feel the SCR system is better, but that doesnt mean there isnt other ways.

Dont let it scare you too much. The pickups dont use much. I just filled our 2011 duramax the other day with 4 gallons of DEF after 7800 miles. Very little cost.


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## nepatsfan (Sep 16, 2004)

durallymax;1340048 said:


> Lots of misinformation in this thread on the SCR system.
> 
> First off SCR is not a replacement for the DPF, they are two different systems with two different objectives. The DPF is for filtering particulates. The SCR system is for reducing NOX emissions. Unrelated to each other however there is a cause and effect that is causing reduced DPF issues thanks to the SCR. But it is due to the fact that the engine can be tuned differently and not because of the actual SCR/Urea. meaning you cant put this on your DPF equipped pre SCR truck and get better fuel economy and fewer issues, thats not how it works. Ill try to breifly explain.
> 
> ...


Could someone summarize this for me? Maybe bullet points or something. Thanks in advance.


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## durallymax (Nov 2, 2011)

nepatsfan;1366970 said:


> Could someone summarize this for me? Maybe bullet points or something. Thanks in advance.


SCR

Reduces NOX by using an Aftertreatment system which injects Diesel Exhaust Fluid (DEF) into the exhaust to convert NOX into water vapor and nitrogen. A system that has been used on powerplants since 70s, and on european diesels and some american diesels for the past few years.

All large on-road trucks with the exception of Navistar and their new truck they built with CAT use this system. Ag equipment is about 1/2 and 1/2. Construction equipment leans more towards EGR/DPF due to current DEF supply infrastructure and handling restrictions. Passenger Pickups all use SCR with the exception of the Non-Chassis Cab Cummins which uses a NOX catalyst system.

Pros:
Allows the engine to burn more efficiently which in turn increases fuel consumption and lowers particulate emissions which leads to cleaner oil with less engine wear, longer oil changes, and fewer Diesel Particulate Filter regens which leads to less wasted fuel.

Requires a smaller cooling package as there is no need to cool immense amounts of recirculated exhaust.

Cons:
The Fluid itself can be a pain for some to handle. In a pickup its no big deal. Every few thousand miles you grab a couple jugs and fill up. The jugs are available in many stores now. For larger fleets, storing the fluid is an issue as it needs to be kept cool and out of sunlight. The cooler it is the longer its shelf life. But it does freeze at 12* and the systems are designed to handle the freezing and thawing of the fluid.

At the end of it all. The new SCR trucks have more power, better fuel economy, and run much cleaner. Butt dynos dont mean much, but the new SCR engines just feel like the chokehold has been taken off of them some and they got their get up and go back.

Their are still downfalls to the system and hopefully someday the engine technologies come along far enough to be able to keep the engine clean without the need for after treatments while keeping power and fuel economy up and weight, complexity and price down.


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