fuel - car will drink as much as your right foot dictates.
dirt... well, you don't drive skylines on dirt, mate
rain, again depends on how heavy your right foot is. I've found myself sideways at a 100km/h while trying to overtake, but then again, it's much quicker through the corners in the wet than say, a commodore or falcon. It also depends on which tyres you have on.
you don't buy a line with your head, cos if you think about it, if you're after a cost effective purchase, an older "performance" car is probably the stupidest thing you can buy.
stick with hyundais