In my last blog I commented that extensive idling or "light loading" of modern diesel tractors can lead to problems with the exhaust emission control syestem. I mentioned that tractors that use diesel exhaust fluid (DEF) need to be worked consistently and "hard" so their exhaust systems will work properly. Kenneth emailed me and noted that it is more correct to say that tractors with a diesel particulate filter (DPF) need to be worked hard in order to keep their exhaust systems operating correctly.
He's right. The short, simple explanation is that Interim Tier IV and Final Tier IV engines that use a DPF in their emission control system can develop problems if they idle at low rpms for extended periods of time, or if they are run at high rpms at light loads for long periods. Those engines need to be worked hard enough to produce enough exhaust and coolant heat to make the emission control system work properly.
Before I put everybody, including myself, to sleep with all this Interim Tier IV, Final Tier IV, DPF, DEF and other gobbledy-gook, let me sum it up this way: If your new tractor has a really complicated-looking exhaust system on it, it would be in your best interest to try to use that tractor in ways that make it grunt at least a little. Either size the load to make the engine "work" more than half the time, or shift up and throttle back when the tractor is dealing with light loads, so that the engine is forced to work harder and build the exhaust and coolant temperatures necessary for the emission control system to work properly.
The owner's manual for tractors with Interim Tier IV and Final Tier IV engines should have detailed guidelines on how to keep the new engines "happy."