If you are only burning 1 quart per 2,000 miles, then this is well within acceptable limits. It is obviously not burning much oil on level ground then. I would assume then that the bottom end is pretty tight and the valve stems and seals must not be too worn otherwise your oil consumption would be higher. I think your inclination that it only smokes on an incline may be correct. Why that is, I do not know. Hopefully someone else may have more ideas as to that aspect.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record