Def, dpf, etc.

[jeffgreef]

Is Mahindra the only manufacturer now with a CUT that doesn稚 have def, dpf, recharge, or any of the other irritating or costly tier IV add-ons?

 

[TheMadOne]

No tractor below 75HP is required to use DEF.

Mahindra and Massey use DOC systems. That is a tier IV compliance addition.

Unlike a system with a DPF a DOC runs at a higher temp at all RPMs and all the time to make the DOC function properly. They also use more EGR than a DPF system. Both of these actions come with fuel efficiency penalties.

There is no free lunch.

 

[jeff9366]

Beginning about thirty-three horsepower most tractors have Diesel Particulate Filters (DPF).
If not DPF, the less used alternative emission technology is Diesel Oxidation Catalyst (DOC).
Both the DPF and the DOC are honeycomb ceramic filters.
The DOC forces engine exhaust over a honeycomb ceramic structure coated with platinum, palladium, and rhodium catalysts. These catalysts oxidize carbon monoxide and hydrocarbons into carbon dioxide and water at hot exhaust temperature.


There is no catalyst associated with a Diesel Particulate Filter. A DPF is a ceramic matrix which accumulates particulates/soot at temperatures below soot ignition temperature. During regeneration, when DPF achieves and maintains 1,100 degrees Fahrenheit accumulated soot incinerates during a few minutes.


Operator Manuals for DPF equipped compact tractors do a poor job of explaining DPFs and a poor job of explaining regeneration cycles. For instance, two manuals i have viewed do not inform that soot accumulates faster during low weather temperatures, none inform time required for DPF to attain 500 degrees fahrenheit, the ignition temperature for diesel soot and none address faster soot accumulation at higher altitudes. It seems to me a DPF temperature readout on electronic instrument panels would address many DPF complaints, as would more descriptive technical writing.


As off-road diesel engines increase in displacement and horsepower emission treatment becomes increasingly complex. DPFs as a final particulate treatment are primarily associated with diesel engines <75-horespower.


Keep in mind emission standards for over-the-road diesel engined vehicles are much tighter than emission standards for off-road engines AT THIS TIME.

 

[jeff9366]

Parked Regeneration is a process on diesel engines with diesel particulate filters (DPF) that temporarily changes the operating settings of the engine to generate extra-high temperatures in the DPF to combust and consume engine exhaust products (particulates/soot) that accumulate in the DPF during normal engine operation.

Soot conversion to ash requires about sixteen minutes once DPF reaches incineration temperature (1,100 deg F.) in warm Florida. Colder temperatures and higher altitude increase soot accumulation.

Forty percent of my Kubota regenerations occur during operation at high-throttle, sixty percent parked. Your tractor operation probably varies from mine.

DPF or DOC, your Tier IV engine has a ceramic-matrix, particulate-eliminator in the exhaust stream. THERE IS NO FREE LUNCH.



Regeneration is an infrequent event for my Kubota three cylinder engine.
Generally once every sixty engine hours. (Consistent in Florida due to warm weather.)

60 hours X 60 minutes = 3,600 minutes.

16 regeneration minutes /3,600 = .00444 = 4/10s of 1% of engine time is parked regeneration.

Fuel cost for sixteen minute parked regeneration @ 2,200 rpm ~~$1.00.



Diesel Particulate Filter supersedes tractor muffler.
At some point in time DPF needs to be replaced.
At some point in time tractors with mufflers need the muffler replaced.

Tire wear and tire replacement will cause as many headaches and more expense than DPF for most long term compact tractor owners who read and comprehend their Operator's Manual.

 

[jeff9366]

Five acres that need grading. Half mile of road that needs snow cleared in winter.

Tractors under 19 kW ( 19 KW = 25.4794-horsepower) are presently exempt from stringent Tier IV emission controls which abruptly increase a tractor's cost above the 19 kW power demarcation.

Every tractor brand includes a model in the 2,600 pound to 2,900 pound (bare tractor) weight range with 100 cubic inch/24 horsepower engine which may serve for your tasks.

The first tractor marketed in this category was the Kubota L2501, today Kubota's highest volume model in Florida.

 

[ericm979]

The HP breaks are at 25.5 and 75. Below 25.5 the requirements are the easiest and can be met without DPF or DOC. Above that a DPF or DOC or both are used. That's with current technology. The requirements are just limits for various pollutants, not mandates for certain technology. If someone comes up with tech that does not use a DPF or DOC that's fine as long as it meets the emissions requirements. Above 75hp the requirements are stricter and DEF is used (again that's how manufacturers are handling it now, DEF is not mandated).

Most > 25.5hp tractors use common rail EFI and the DPF ones use high temp discrete regens. Branson uses a low temp DOC+DPF with continual regen, and that allows them to use mechanical fuel injection. Like all technology choices there are plusses and minuses to all of them.

With the execption of a few models, most problems with regens are operator caused. Either the operator panics when the regen light comes on and cancels the regen and keeps doing that, or the operator runs the tractor at low rpms too much, or both.

 

[jeffgreef]

Thank you gentlemen for your thorough explanation of these technologies in general.

My question was whether Mahindra is the only manufacturer that produces a CUT without the use of these technologies, or, using only those that are not costly or problematic (DPF). Mahindra claims that their common rail diesel requires no DPF or process of regeneration, due to their investment in engine design. They have a DOC, which, as I understand it, functions similarly to a cat converter on a car and presents no additional input from the operator. DPF requires regen, and the filter itself must be replaced periodically and is very costly to do so. DEF is irrelevant in this range.

I don’t want to get a tractor which will require a periodic process of regeneration, or the replacement of an expensive filter numerous times throughout its life.

So that is my question- WHO is producing what, and what manufacturers tractors in the 40hp range do not use DPF.

Is it only Mahindra and Massey?

I’m not looking for a free lunch and don’t need to know, in general, that most tractors use this or that. I wonder if anyone is keeping track of, specifically, WHO is using WHAT.

Thanks

 

[ericm979]

The DPF should last 3000 hours. Few people will get their CUTs to that. DPFs don't have to be replaced when they clog. They can be cleaned. There are many companies that offer that service for the trucking industry.

Branson's DPF does not require a regen process.

 

[Motorboatin]

Is it only Mahindra and Massey?

Yes but Branson has a DPF system that doesnt go through regen cycle. I have no idea how the Branson system works

I have a Massey and so far it just runs like my truck without the need for DEF

 

[jeffgreef]

Well I just don’t want to get a tractor that will be a pain in the neck with the need for regeneration, clogged dpf filter, and the expense of replacing them. I’ve read that dpf filters will require replacement much sooner than 3000 hrs.