/\ AGREED /\
I'll go a little farther. I've never seen a situation in which a straight six, with the right gears and tires, wouldn't get the job done OFF-ROAD.
I have seen some situations in which a little more power allowed for more civilized highway gears without unduly compromising the of-road performance.
The ability to pick your line while driving off-road seems to be a drying art. It saddens me a bit when I see someone whose only solution to off road obstacles is wider tires and more horsepower.
Tall skinny tires (AKA Pizza Cutters), the right gear, low end torque and a little common sense; will get you through places that horsepower and fat tires will not. The exception to the skinny tires is when operating on mud or sand that has no bottom. Sometimes you need to spread that load over a bigger footprint and a fat tire is the solution in those conditions.