Originally Posted by Model16
Don't know first hand, but a buddy has one of the diesel military ones, and supposedly he gets 16+
The 6.2L diesels get pretty good mileage. 15+ around town, low 20's on the highway. Unfortunately, they are extremely slow. The torque gets them going off the line, but after about 20mph or so they just die. The later 6.5L was better, but diesel Blazers/Yukons of that generation are hard to find.