what is lugging and how does it happen?

Lugging, as far as I know, is just working the engine at a lower RPM than it should, or wants to be at.

Lugging is death to an engine.

All engines have a "power band", from a certain rpm where it starts,to a higher rpm where it ends.Below the minimum,you will lug it.Above it,you will be past the power band.Typically gas and smaller displacement engines make power at higher rpm's than bigger displacement or Diesel engines.

Actually a lugging condition exsits any time the load on an engine is high enough to force the engine to loose RPM at full throttle. In other words, if the engine cannot pull a load and looses RPM it is lugging.

Just listen to just about any Harley that is posing/parading around with nothing better to do, it is usually lugging around.

Like stated above, it is Death to an engine!

And that is why I keep it reved up to the maxx!!!!!!!!!!

Imo it's only possible to do with a manual tansmission. An auto will just down shift.

Actually a lugging condition exsits any time the load on an engine is high enough to force the engine to loose RPM at full throttle. In other words, if the engine cannot pull a load and looses RPM it is lugging.In my opinion,not until you get under a certain rpm.

You could also describe it as loosing speed while maintaining RPM or not gaining speed while RPM is increasing. More often then not like was said before, an auto will shift once the go pedal is pressed. Another good point that I saw above it that gas engines would lug more then diesels. That also is true.