We have heard that a major con of the new tier 4 engine is a higher initial price and higher maintenance costs. However, can anyone say exactly how much those higher maintenance cost would be compared to older engines? Also, there should be some pros. I realize that the engine itself is much much quieter, but what about fuel usage per hour compared to older engines?
Specifically, I am curious about the 5083e versus the 5085e.
Also, can anyone explain this regen I keep hearing about and how it works?
I have extensive experience in the trucking industry and operating DPF equipped trucks. I know that doesn't exactly translate to the tractor market, so take my info for what you will.
Particulate filters have one job, to catch soot particles. That's all well and fine, except that anything that catches a contaminant, must be cleaned or replaced sooner or later. Now, the way DPF's clean themselves is by doing a regen burn. This is basically the machine injecting raw fuel down the line in the exhaust system to create extremely high exhaust gas temperatures. It takes a ton of heat to "burn off" the soot particles trapped in the filter. In the trucking industry, DPF's were installed on trucks starting in 2008. The exhaust gas temperatures during regeneration were so hot, they actually discolored the chrome smoke stacks. Thicker stacks with higher quality chrome plating were introduced to stop this.
The trouble with any kind of "cleanable" filter is that you can never clean out 100% of the contaminants in it. DPF filters never burn off all the soot accumulated. What happens down the road is eventually the DPF will need to be replaced because it simply will not function correctly anymore. These are not filter cartridges like an air filter, these are large metal filters that cost thousands of dollars to replace and must be done by a qualified shop. Now, tractor ones will be much smaller, but I would be willing to bet they will still cost over $1,000 to replace. Tractors do not see the kind of heavy use that big rigs do, so this may never happen. I am simply communicating to you what can happen with these systems once they get older.
Now, the lighter you work your tractor, the better, right? Wrong. Not on a DPF equipped machine. Light use and low engine work load means low exhaust gas temperatures, and higher soot content. Literally, the easier you are on your tractor, the MORE soot will accumulate in your DPF, and the more regen cycles you will need to do. The only way to keep the minimum amount of soot from being created, is to constantly work the snot out of the machine to keep EGT's high, resulting in a much cleaner burn and less soot particles for the DPF to catch. The downside to these tractors is you really can't work them hard enough unless your doing serious ground engagement. Regular loader work and backhoe work will never create high EGT's, that just isn't hard work. The optimal situation for a well performing DPF is for the engine to be at, or near, 100% load, as long as it's running. Obviously that is almost impossible.
Since regeneration cycles require more fuel to be used to obtain higher EGT's in the DPF, I think you will see a slight increase in fuel consumption.
In the trucking world, everyone I know is keeping their trucks that are pre 2008, and simply rebuilding them. Emissions equipment has been extremely problematic since it's introduction, and sadly, will never go away. The cost has been huge, the reliability is non existent, and performance is down.
Now, keep in mind, the John Deere system on small tractors is a lot different then the trucks I mention. However, a DPF system is a DPF system, it all functions the same, it's just a smaller version.
