A) Agco has an iT4 engine with no EGR on it. Most fuel efficient tractor ever tested in Nebraska and Europe.
B) Final Tier 4 will required EGR and maybe DOC/DPF. Deere is going with a DPF system, which means they also need the EGR.
C) SCR engines are more fuel efficient because they are optimized for power and fuel production, not for exhaust gas recycling. SCR actually helps with particulate emissions because the combustion process is optimized (again because exhaust gases are not recirculated).
D) Agco's SCR equipped tractors cost the same as EGR equipped versions. And SCR is probably cheaper to manufacture than EGR too. Small additional tank, pump, metering, nozzle and catalyst chamber, and ECU. Sounds a lot better than DOC/DPF. And about filling an additional tank... no big deal. Either way you'll have to fill up either a smaller AdBlue tank or the diesel tank. Personally I prefer filling up on AdBlue than diesel
E) I must be the only person in the ag world to agree with the emission regs... I want my kids to live in a clean world, but it sounds like most people don't care about anyone who will live after them. Just my .02
I may have typed to soon as to what the Ag company's are doing to meet the new regs. I mainly based my statements on what the new diesel pickup and OTR trucks are doing. The 2010 1/2 Ford, GM and heavy Dodge all have EGR, DPF, and SCR/urea injection. From test results that I have read fuel efficiency has not been improved and operating cost has taken a jump because of the increased manufacturing/initial purchase cost and the extra cost of DEF-Diesel Exhaust Fluid. A diesel engine option in a 2010 pickup truck is 12 grand+. DEF is projected to cost about what diesel costs. My thinking is it is going to end up costing much more tho as DEF is urea our main nitrogen source used in fertilizer. In the next few years as more and more diesels world wide start to use urea just think what its going to do to fertilizer prices. It also has several problems in its self, mainly its very corrosive and it freezes. So the whole injection system has to be heated. The government is always screaming about conserving natural resources but their very regulations cause large reductions in fuel efficiency and increased usage of other resources [Urea] to meet their regulations. What's next?, CO collectors that scrub CO from the exhaust, bottle it and require us to pay to put it in some type of storage?! I better quit I'm probably giving someone some new ideas to make our life harder and our bank accounts smaller.