# Tractor w/DEF or Tractor wo/DEF



## weatherman (Dec 5, 2008)

I will be upgrading to a bigger utility tractor from a Kubota M6800 2wd w/FEL. The Kubota did me justice for the past 6 years. The tractors I have been looking at either used DEF or not. Still trying to familiarize myself with these other acronyms (EGR, DPF) of there plusses and minuses. When I get a brain freeze trying to comprehend this EPA BS I take a trip to the barn at the JD model A. I reviewed plenty of HT posts from 5/6 years ago. At that time, posts were pretty negative towards DEF tractors. Has the “DEF technology” got any better? What about sub-zero temps...any serious issues with DEF? My dually F350 DEF heater went bad which I replaced, do these DEF type tractors use heaters?


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## slowzuki (Mar 8, 2011)

Yes they use heaters. Buy good urea/def, be mindful of sticks etc poking up around the wiring harness as there’s more wires and sensors than a normal fuel tank. All the DEF tractors around here that I’ve run have been great. A Deere had some issues when new that the DEF was blamed for but in was a pinched fuel line and brake line. Neighbours kubota threw a code but was a branch unplugged a sensor, easy fix. Friends 135 hp Kubota has been good, uses very little DEF except when under heavy load.


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## Tx Jim (Jun 30, 2014)

I personally would not purchase a diesel engine with common rail injection. My neighbors Kubota M8560(tier lV) got water in tank with lead to fungus in fuel which lead to new fuel system to the tune of $8000 repair bill. I accidentally got water in my Kubota M7040(tier ll) fuel tank drained water & changed fuel filter problem solved.


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## slowzuki (Mar 8, 2011)

I don't believe it can be avoided in any new tractor, they are all running high pressure injection via one method or another that won't work with water.



Tx Jim said:


> I personally would not purchase a diesel engine with common rail injection. My neighbors Kubota M8560(tier lV) got water in tank with lead to fungus in fuel which lead to new fuel system to the tune of $8000 repair bill. I accidentally got water in my Kubota M7040(tier ll) fuel tank drained water & changed fuel filter problem solved.


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## Tx Jim (Jun 30, 2014)

slowzuki said:


> I don't believe it can be avoided in any new tractor, they are all running high pressure injection via one method or another that won't work with water.


I agree so engineers should come up with a fuel system that water doesn't do as much damage to the fuel system & evidently common rail isn't the answer.. Diesel fuel has been getting contaminated with water for as long as I can remember & that's a lot of yrs.


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## Gearclash (Nov 25, 2010)

EGR = (Cooled) Exhaust Gas Recirculation. The purpose is to reduce the temperature of combustion and therefore reduce the amount of NOx the engine emits.

DPF = Diesel Particulate Filter. This is to catch the soot (smoke) in the exhaust.

DEF = Diesel Emission Fluid. Used in systems with SCR (Selective Catalytic Reduction) which is an alternate to EGR for reducing NOx.

Many diesels use both a DFP and either EGR or SCR to control pollution as they are aimed at two completely different forms of emission and each pollutant tends to form under different combustion conditions. NOx is a product of high temperature combustion, soot is a product of low temperature combustion. CNH has been using an SCR only system for a little while now, my assumption is that they tuned their engines radically in one direction so as to only need to deal with one pollutant.

My feeling is that cooled EGR has been a bigger pain than either of the other systems.


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## SVFHAY (Dec 5, 2008)

Have 2 NH tractors with def/scr, 2000 hours so far and no issues, nothing. Use 50 gallon def per year between the 2. It can freeze up but I am told they have heaters. Mine stay inside heated building so no practical experience.

I know it's a matter of time until they do make problems but it's kinda nice to start them up inside and not be smoked out. The 4020 will leave you gasping in short order.


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## Tx Jim (Jun 30, 2014)

slowzuki said:


> I don't believe it can be avoided in any new tractor, they are all running high pressure injection via one method or another that won't work with water.


My point was that engineers should develop a better fuel inj system that water doesn't destroy.


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## Gearclash (Nov 25, 2010)

Tx Jim said:


> My point was that engineers should develop a better fuel inj system that water doesn't destroy.


Given the close tolerances needed to make the high injection pressures I don't think it will ever be possible to make a modern injection system tolerant of water. The only hope is to make the filtration system catch absolutely 100% of any water that comes along. I don't like the cost associated with high pressure common rail systems either, but at this point there is no other way of achieving the control over the injection process needed to accomplish the reduction in emissions that the manufactures are forced to meet. There are some practical benefits to high pressure common rail injection as well. One is quieting of the diesel engine. Between eliminating the injection pump clatter and eliminating the "diesel" clatter of ignition, these engines can be a lot quieter. The bigger benefit is the ability to reduce the peak cylinder pressures at which the engine operates when under full power, but hold the peak pressure longer. This results in an engine with a higher torque and horsepower output with less stress on the components.


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## slowzuki (Mar 8, 2011)

Luckily it is pretty easy to add better filtration between the tank and the common rail high pressure pump. My 2012 ram had just the tiny filter at the engine with the water repellant treated element, have had trouble with it for both dirt and water so bought a kit that adds a big honking spin on filter on the frame like the newer trucks.


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## Gearclash (Nov 25, 2010)

Yes, that was a major boo boo that Dodge made. They had I think an 8 or 10 micron fuel filter from the factory when it should have been a 2 micron. They started that foolishness all the way back at the beginning of the CR engine in MY 2003.


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