Tinman wrote:
High load, low rpm is far more deleterious than the same load a higher rpm. "Lugging" puts a lot more force/wear on bearings and engine internals than rpms. Of course, the higher the duty cycle, the more wear/shorter life. Hard to lug a automatic though. Don't worry about it, drive it. It's probably good to do a full throttle run every now and again to get the cylinder temps and pressures up to clean out the combustion chamber.
I have been reading these statements and I am trying to figure out who came up with the info.
Most modern (last 5-6 years) are designed to lug and putting them at high RPM or redline is not a good idea.
Case in point... ALL CAT, Cummins, Volvo, International, Mack, etc engines are designed to operate at lower RPMs than earlier models. It is not uncommon to "lug" them down to 1000 RPM even under an 80K lb load. They operate best and most effectively at 1300-1400 RPM. This is the middle of the power band.
Likewise, the VM reaches it's peak torque at 1800. The torque drops off starting at 2500. Therefore the power band is between those two values. The engine is designed to operate best in that range and diesels do not need to be run up to "clean" them out.
I know that some may disagree, but having put close to 3 million miles on various diesels including 1.4 million on my last Freightliner and not EVER having a major problem or losing a turbo I got a good feeling about my comments. I presently have over 300K on my Volvo and REGULARLY "lug" it down to 1000RPM and NEVER rev it above 1600 and it runs like a champ and pulls the hills great. I regularly operate it at about 1300 RPM and it purrs like a kitten.
Some of those out there need to get out of the 20th century regarding diesels and catch up to the new technology. Thing have changed quite a bit in the last few years. Since this is important to my business, I put in a lot of effort in studying the newer engines. at $25K a pop for an engine, I can't afford to play games with how they are supposed to operate.