Nice job with the graphics, sound and physics.
When I play it my best score doesn't update. It always shows it as 0:0.
It seems a bit strange fuel goes down at an even rate, personally I think it'd be a much better mechanic if it went down very slowly when the vehicle is idle, but went down at a faster rate when accelerating. That would make me feel more pressure to make it up a hill first time.
Trying to play on a desktop is tricky with pedals either side of the timer. I'd rather they were next to each other, or at least a lot closer together to save me constantly having to swipe my mouse back and forth. I expect they're positioned at the moment with mobile users in mind which makes sense, but if it's also for desktop users it'd be good to have a setting to change pedal positions as an option.
One thing i felt the game lacked was anything that differentiates it from others in the genre, like Hill Climb Racing. The first level says it's called 'Village' but I've not seen a single house or anything on the topic of a village, if it's going to be called village I'd rather there were things in it that gave it personality, on the first level you just go up and down hills and collect coins worth 5points, and that seems to be it. Be much more interesting if you could run over the odd sheep or cow that's escaped from a village and get bonus points.
Overall it is a nicely made game, just lacks that depth to make it worth keep playing. When lots of people have already played other games like this to death it needs fresh aspects to make it worth coming back to.