I'm looking at a pretty nice '88 2500 6.2 with 185K miles. Looks well maintained, oil changes every 3K, but owner says he adds about 1 quart or less in between. Is this typical oil consumption or is it high? I never have to add any oil between changes on my F150 gas.

GM's spec is 1 litre per 1000 km's so yes, its acceptable and average. On a related note, mine doesn't use any oil between oil changes, I go 5-6000 km's, :D

1 qt per change. That's about what both my 6.2's use

My 84 with 187K uses a quart about every 1500. I change at 3000, Shell Rotella.

My pickup uses a quart in 2000 mi. The Suburban, not a drop!

my burb used to use about a 1-2 litres every 5000 KM, now it uses 1 every 5000 km..diesels leak, burn, and spit oil when they feel like it....it's in their nature...they're like the "bad" baby:P