There are two technologies in particulate filters. One traps carbon particulate and then burns then off occasionally. They burn off two ways, either a separate electric burn off, like your charcoal starter, or the injectors put some raw fuel in the exhaust stream were it burns in the filter, most popular. The ECU manages this and is invisible to the operator except you might notice the smell when the ECU decides to burn the particulate. The EGR valve is able to be cleaned but may be hard to get too. On a VW the part is $80 or close. On a diesel car you can see EGR issues at as few as 50k miles. VW will give you one cleaning under warranty. Running clean fuel is important and using additives become more prevalent. People who run 5% bio or power service diesel kleen report EGR issues are much less an issue. Not sure how tractors are going to do we are in uncharted ground now. The AG blue or the catalytic converter technologies to go after the NOx are not problematic. With an AG blue system you will have to keep a reservoir filled, but its down stream of the engine and will not effect the expensive thing; your engine. The catalytic converter technology is expensive to replace but requires no special attention, and in an diesel automobile is easy an 100k mile part, not sure how it might do in a tractor operating environment. High pressure pumps can be a problem, are very expensive and in a failure can destroy the engine. Ford has major issues with theirs, google ford Diesel engine failures. BMW had issues with one on a direct injection gas engine. There is no skimping on the quality of materials and assembly in these pumps. Automobiles are driven different then tractors. Tractors sit allot, and may have many short operating periods, start, stop, start, no ones how the system will do under those conditions. If your color is using their own designs and parts you might go through some growing pains as they make their system reliable. If your color had Bosch/VW, MB, or BMW design and produce those parts I wouldn't worry at all you could have very well got a better machine. The problem is no one can tell you how say Kubota developed their system and who makes the injectors, high pressure pump, and other parts in the system. These modern diesels produce more HP, get much better fuel economy, are more responsive, are much more quite, and are very, very, clean. The question is are they suitable for tractors? I understand how they work, and drive a BMW 335d. Have had a TDi VW and have followed the technology very closely as it has developed over the last 13 years. I bought a new tier 3, Kubota
L3800 a few months ago before the change. Not enough information for me to make a choice. I almost moved on the Yanmar, they make great diesels and I know they have a partnership with BMW to develop their system, I would put money it's trouble free. This direct injection technology is currently flowing from diesels to gas cars, with and without turbos, it's how all engines will operate in the next few years. HS