Stricter Tier IV off-road diesel engine emission reduction standards phased in dealer tractor inventory during 2009 - 2012, impacting tractor prices.
Tier IV emission standards require tractor manufacturers to add or revise pollution reduction technology on new tractors generating over 19 kW power = 25.4794 horsepower.
What about BX2670 and 2670-1 for example that are close to that threshold?
Some manufactures can meet Tier IV requirements without a Diesel Particulate Fillter on low engine displacement, relatively high rpm engines powering ~2,000~ pound bare weight tractors up to 27 horsepower.
Sufficient tractor weight is more important for most tractor applications than increased tractor horsepower.
DPF is used by the majority of tractor manufactures for emissions control on OVER 24.4794 horsepower tractors.
Tier IV technology complicates the engine and exhaust package and is a significant cost factor. Tier IV technology tractor emit only about 1% of the pollutants emitted by a pre-Tier IV tractor.
Diesel Particulate Filter (DPF) captures exhaust particulates (soot) in a ceramic matrix. When tractor engine runs sufficiently hot, accumulated particulates burn off periodically without operator intervention. If engine is not run continuously hot long enough to burn off particulates, diesel soot accumulates in the matrix. Once heavy soot accumulates in DPF the tractor forces soot clearance with the tractor parked and throttle open to about 2,200 rpm for about sixteen minutes, which makes the DPF REALLY HOT to burn off all accumulated soot. Burning off accumulated soot, either during operation or parked is called REGENERATION.
Regeneration is an infrequent DPF event with my Kubota three cylinder, 37-horsepower engine. Generally once every sixty engine hours. (Very 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 consumed during parked regeneration.
Fuel cost for sixteen minute parked regeneration @ 2,200 rpm ~~$1.00.
Forty percent of my regenerations occur during operation, sixty percent parked.
The average residential tractor operates eighty engine hours per year, according to industry surveys.
3,000 hours DPF Life / 80 hours = 37.5 years of residential use prior to DPF replacement.
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.
