My 8, an 1989 model has an overgrown Lawnmower engine, 18 horse Kohler that seems to run forever on a tank of gas. I have never had to refill the tank, be it a 10 day hunt or a long weekend with the kids running it everyday all day long. 32 litre, (7imp), (8.4 US Gal) Has 2 forward, a neutral and reverse gears. Not a speed demon at only 35Kph but a real work horse. She has carried Moose out of areas that My buds couldn't even begin to get their Polaris Quads into. Very smooth riding compared to a quad over the rough stuff as you have 8 wheels spanning the rough stuff.. The tires are the only suspension and I run mine at 3.5 - 4 psi (ie) will travell over a 3 ft diameter by 3 ft deep hole at an idle or full speed and you would even know the hole was there. Really smooths out those meadow moguls. The newer models are much easier and nicer to drive and I would recommend you get the 8 and not the 6 because of the carrying capacity.