Well today at 49 hours I had my first regen. This tractor is a 2015 that I bought new in February 2016 from Muttons in Ft. Wayne IN. I did not take possession until April 2016 because the 240 loader was backordered. I put on more hours in winter than summer if its snowy, but it hasn't been, hence the 49 hours. I have been careful to avoid excessive idle time or anything that could lead to DPF plugging. Anyway, I was out mowing and the orange exhaust temperature indicator came on and the pitch of the engine changed. I could literally feel the heat of the engine and exhaust from the seat. (OOS). Having never had a tractor with a DPF system I did go get the owners manual and quickly read through it, setting the throttle at 2000 RPMs while I did so. In typical John Deere fashion it was vague and uninformative. The regen took about 55 minutes, and for the most part I just kept mowing. When I did stop, I kept the RPMs at 1800 since that's what JD says a PARKED regen requires. There was nothing I could find in the manual that says how long a regen should take or what RPMs it should be operated at...but I may have overlooked this. I was kind of nervous...I hate all this emission crap. I own several diesel trucks with DPF/DEF systems there in no question it has compromised the longevity, reliability and ownership cost on each one. If this only happens every 50 hours I can live with it. Before I bought this tractor I read the competing brand's regen horror stories...and came to the conclusion JD had the best system. I still think that's true. As I said I only have 50 hours/2 yrs 2mos...but so far its been a good tractor. Its easy on fuel, stops on a dime, climbs like a goat, tons of power and heavy enough to do real work.