Off road, even the 2.61 low range is barely able to make up for the 3.08 axle gears, providing less than adequate power for off-roading. Now add a set of 33-inch tires, and even at 60 mph the engine is lugging around 1,800 rpm, way out of the powerband of this engine. (4wheeloffroad)

The friction point can be felt with the car starts moving, and engine RPMs drop usually along with the noise of the engine. This is also the point that many beginners let the clutch out too quickly, resulting in the engine lugging and the car bucking. (standardshift.com)

Actually, the way I learned because i was trying to save gas, was to shift into the next gear at the minimum speed so that the car wasn't lugging. Lugging is when you're not going fast enough for a higher gear so your car kind of groans as it moves because that particular gear gives too much speed and not enough power for your speed. (www.ehow.com)