I dont know what the wheelbase is on most rovers, but the hummer, hell yeah it isnt allowed. The hummer sucks offroad!

Sure its wide and maybe be able to go over wide ditches or something but most trails are in wooded areas and its pretty hard to find any big enough for a hummer, its long enough that you'd have a hard time getting around many corners as well as difficulty with high centering, but you'd also have to cut down all the trees to get through

Most real offroaders wouldnt want a hummer

The hummer might be better suited for more open terrain than what we have int he midwest.