A 40-horsepower tractor will allow you to spin a 72" Rotary Cutter through very tall grass.
15 acres X 3 times per month is 45 acres. For me, a 72" Rotary Cutter would be minimum.
I have a 2013 purchased, Tier IV / DPF tractor. Most of my work is in woods, so it runs at moderate revs.
You can run a Tier IV tractor slow but you cannot regenerate during tractor work at slow rpms. The alternative is to park, then perform an active regeneration, which requires parking, then setting the throttle to 2,200 rpm for around 16 minutes to heat the DPF sufficiently to incinerate accumulated soot. Parked fuel regeneration cost $1.00.
Tier IV emission controls and DPFs began to phase in dealer tractor inventories ten years ago.
Old news in 2019.
Consensus considers DPF problems 90% caused by operators who do not carefully read regeneration procedures in Operator's Manual or refuse to follow the procedures. Many small property users regenerate just once per year. This creates regeneration procedure uncertainty in itself. (Regeneraton occurs every ~~60 engine hours. Non-commercial users average 80 engine hours per year.)
Operator Manuals for DPF equipped compact tractors do a poor job of explaining DPFs and a poor job of explaining regeneration cycles. Most manuals do not inform that filter soot accumulates faster during low weather temperatures, none inform time required for DPF to attain 1,100 degrees Fahrenheit, the ignition temperature for diesel soot and none address faster soot accumulation at higher altitudes. It seems to me a DPF temperature readout on electronic instrument panels would address many DPF complaints, as would more descriptive technical writing.
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.
Tire wear and tire replacement will cause as many headaches and more expense than DPF for most long term compact tractor owners who read and comprehend their Operator's Manual.
