Billy--- The BFG - Rugged Trail only has 10/32nds tread depth when they're brand new off the shelf. So compared to say a General - Grabber AT2 which has 17/32nds brand new-- then yes, the BFG - Rugged Trail will have a short life right from the start.
What makes the BFG - Rugged Trail so unique is it's the ONLY "P"-series tire made in size 275/70R18 with a tall O.D. of 33" and only weighs a featherlight 46 lbs each. Take a peek at TireRack.com for all tires made in 275/70R18 (33" O.D.) and you'll quickly discover that all of the rest are much heavier "LT"-series tires easily weighing 10 lbs more in the ballpark of 56 lbs each.
Remember; for best MPG we want tall O.D., narrow width, and super lightweight all combined in one tire. Class dismissed.