Def, dpf, etc.

[MaineGuy1]

My point is you are still putting diesel (dirty fuel)into the engine. Something has to be different than a engine prior to Tier 4 in all cases (DPF, DOC, etc). So just because an engine doesnt have a DPF doesnt mean it isnt doing something else that will require maintenance down the road. For instance the Doosan engines in the new Bobcat Skid Steers uses a special fuel filter to micronize the fuel particles as before they are sucked into the engine (allows more efficient burning of fuel...less soot). These filters are expensive, and also are must more likely to clog (especially in cold weather). The filters have to be replaced every 6 months or so. There is no DPF so the Bobcat much be great right? Not when you dig into what was changed to make it Tier 4 compliant. I am not saying the Massey is the same, I am saying you should dig in and find out what compromises were made to meet Tier 4.

As far as the tractor brands.. Massey started last year. Mahindra has had them for a bit longer.

Just curious what maintenance I will have to do on my Shibaura engine with DOC? My dealer says I have no maintenance to do on it because of the new emissions standards. I understand what you are saying about the Tier 4's, but one of the selling points to me was when my dealer said there is no special maintenance just because it is a Tier 4.

 

[jeffgreef]

That’s my understanding, that a tier IV compliant engine that uses only a DOC needs no maintenance such as the regeneration and ash cleaning required with a DPF. Is that a Shibaura tractor you have, or is it another brand tractor with a Shibaura engine?

I wonder if DOCs will last the life of the tractor like a gasoline catalytic converter does in a car.

 

[MaineGuy1]

That’s my understanding, that a tier IV compliant engine that uses only a DOC needs no maintenance such as the regeneration and ash cleaning required with a DPF. Is that a Shibaura tractor you have, or is it another brand tractor with a Shibaura engine?

I wonder if DOCs will last the life of the tractor like a gasoline catalytic converter does in a car.

It is a Massey 1735M. I wa told the DOC lasts 5000 or 10,000 hours. I don’t remember which because this probably is not my last tractor and I won’t hit those hours.

 

[finn1]

My point is you are still putting diesel (dirty fuel)into the engine. Something has to be different than a engine prior to Tier 4 in all cases (DPF, DOC, etc). So just because an engine doesnt have a DPF doesnt mean it isnt doing something else that will require maintenance down the road. For instance the Doosan engines in the new Bobcat Skid Steers uses a special fuel filter to micronize the fuel particles as before they are sucked into the engine (allows more efficient burning of fuel...less soot). These filters are expensive, and also are must more likely to clog (especially in cold weather). The filters have to be replaced every 6 months or so. There is no DPF so the Bobcat much be great right? Not when you dig into what was changed to make it Tier 4 compliant. I am not saying the Massey is the same, I am saying you should dig in and find out what compromises were made to meet Tier 4.

As far as the tractor brands.. Massey started last year. Mahindra has had them for a bit longer.

The Doosan fuel filter is nothing more than a very low micron filter that protects the 45000 psi high pressure common rail fuel system from mechanical damage caused by dirt in the fuselage.

The high pressure fuel system is the emission control feature, not some magic fuel filter. Extremely high pressure fuel systems cannot tolerate dirt in the fuel.

They also incorporate fuel heaters and engine warm up strategies to protect against the inevitable effects of fuel clouding ans subsequent fuel starvation when a low micron fuel filter plugs in low temperature operation.

 

[jeffgreef]

Finn1- but still Jchonline is saying that the Doosan filter is something that requires extra maintenance and attention to meet tier IV. His point (I think) is that there have to be compromises somewhere to meet tier IV, and this will inevitably result in extra money, time, repair, inconvenience for the operator. But it looks to me like Massey and Mahindra, at least for tier IV CUTs, have found an engineering/technical solution that does not create any extra bother other than the up-front cost of the machine. Replacing a DOC after 5000 hrs is no different than a valve and ring job- nothing lasts forever. Replacing expensive filters frequently, and dealing with them clogging in cold weather because the fuel line heater quit is the kind of pain in the neck I want to avoid.

 

[finn1]

Yes, the filter requires extra maintenance because of the low micron rating. From memory, a normal fuel filter is something like a five micron rating element. As one reduces the micron rating, finer particles are trapped, meaning that for a given volume of fuel passed through the filter media, the filter has a shorter life before flow restriction increases to the point of the filter becoming effectively blocked.

Doosan has doubled the size of the media compared to typical filters used by their competitors to counter the shorter life, to some extent. If you do a search, you can find a Doosan / Bobcat PowerPoint presentation that covers this, with, of course a little spin.

The same presentation explains the requirement for a fuel heater for low temperature operation, and how they incorporate a warm up strategy to reduce power for the first several minutes of operation to counter the ill effects of reduced filter flow with cold fuel, which has poor flow through the low micron filter as the fuel becomes viscous as it nears the cloud point.

There’s no free lunch here.

A well engineered DPF will last 3000 hours before it requires cleaning or replacement. There are now commercial services out there with equipment to clean a filter, so I don’t see the big deal.

At the current rate of about fifty hours per year, that’s what, sixty years of use for my CUT. I don’t think I will be breathing, let alone using the tractor in sixty years when the DPF needs its first cleaning.

 

[deserteagle71]

As I said before, the main difference with the Tier IV tractors is that, whether it is equipped with DOC or DPF, is that rpms have to be kept up and idling kept at a minimum. Before ending up with my Kubota I did extensive research on Branson, Mahindra and New Holland also, all of which used the DOC system. ALL of them recommended minimizing idling time so that the exhaust is kept hot and the particulates are constantly burned off. (I can't speak to a Massey or any of the other brands, didn't research them.)

So really, the main operating difference between any "old" tractor and "new" ones with Tier IV emissions is that you have to avoid running the Tier IV engines at an idle. But that's true, really, for any diesel. They all do better if they are run hard and kept hot.

 

[wagne223]

As a first-time new tractor buyer, I want to be very careful about what I buy, and particularly because it will probably be the only new tractor I ever buy. I’ll use it a lot at first and then very little, held in reserve for snow clearing. Anyway, I don’t want a problematic machine if I can get one that doesn’t have those problems.

I don’t recall where I read that DPF filters will need frequent replacement and now it’s clear they do not. However, they can become clogged through operator error and will eventually need to be professionally ash cleaned. Some people have problems with these things and these problems all flow down to the dealers, as we see from posts above. I’d rather avoid these problems altogether and have a reliable unit that requires a minimum of maintenance. That’s why my original question was- which manufacturers of CUTs don’t have them (still unanswered- I guess just Mahindra and Massey).

Why don’t I just get an older used one without it? I have been scouring craigslist for years now just to become familiar with the used market for when I eventually buy. Finding exactly what I need in hp range with quick-attach loader, midmount pto, extra hydraulics, frame-mount backhoe etc. in the used market is pretty rare. I could get a used one without all this and add it on, and in the end spend about the same money as buying new. Might as well get the whole package at once.

One more chip in the pot is I would like to be able to operate with 100 percent biodiesel. Perhaps for this reason I must buy older used, since even Mahindra, without DPF, says not to use biodiesel in the new units because they are engineered to run on dinosaur oil.

For pro operators who are used to keeping track of multiple maintenance issues on multiple machines, the extra minimal issues with DPF are minor. For ‘hobby farmers’ and other part-time operators like myself it’s just one more problem that can be avoided. As well, as the technology advances, probably all manufacturers will develop systems without DPF, like Mahindra and Massey. Then, the tractors made from 2013 to 2022 or so that DO have it will be seen as undesirable for resale, an older problematic technology like the smogged-out cars of the late 70s. This is of little concern to pro operators who aren’t thinking much about resale because they are going to use the machine through most or all of its life anyway, but for us non-pros, resale of a 15 year old unit with 1000 hrs on it is an important factor to consider.

If you plan on using 100 percent biodiesel, then you should not be concerned with the type of particulate filter your tractor has.

Biodiesel is very clean burning.

Plus You will be spending too much time dealing with fuel related issues and trying to keep the machine running then worrying about whether or not the machine has to regen or not.

 

[wagne223]

But to answer your original question,
Yes, the 2 you mentioned are the leading ones that use the DOC system with no regen.

It should be mentioned, however, that the top 2 selling tractor manufacturers in this class use the DPF system.

To my knowledge, of these 2, only 1 model from 1 manufacturer has had repeat issues. Which have since been worked out.