reviving an old thread yet again but to respond to the questions on DPF clogging. For anyone who has operated an early mechanical diesel motor at various altitudes, you can see that the vehicle may not make any smoke at all at sea level but at higher altitudes the smoke / particulate matter level increases greatly! Especially during high load / low boost launches. This is due to the air being less dense, less O2 vs. sea level, and same amount of fuel getting pushed from the injectors. Now, applying this with a DPF, you can see that the DPF will get clogged much quicker due to much higher rate of particulate matter (black smoke) at higher elevations. All I can say is, if you're at higher altitudes, get the 5220 turbo and try to not rev it from idle under load. Might make more sense to opt for a hydrostat unit so you can keep the RPMs up and turbo spooled at all times rather than revving it up and down, blowing smoke at each acceleration forward and rearward during loader work, etc.