Proper knobblies would be in order I think. But it's not "bad" on the standard tyres, so probably not worth changing for occasional green laning (drop pressures should be OK), but for more frequent or serious offroad stuff you'd need to get gnarlier tyres. Tend to get about 170-180 before the Empty flashes, then there seems to be numerous litres after that. I reckon 230-250 miles per tank easy enough. Maybe I'll do the "put a spare fuel container on the back and ride till you run out" challenge. We're metric when it suits us That'll be "tuppence" Norman.