Great interpretation of the theme! And interesting combination of vehicle handling and fuel use strategy. I wasn't able to beat the 3rd level, and based on the giant arrow spinning around erratically and then disappearing, I figure the ambulance rolled away out of the world or something?
Feedback for improvement. The engine audio is really cool. You could improve it further by shifting the pitch as the car accelerates. The car also topples over seemingly at random (could just be because it's hard to see the terrain sometimes). The terrain visuals are also identical between the 3 levels I played. You could explore hue-shifting the colours somewhat to add a bit of variety (either the terrain, or the sky, or both), would make it look super pretty! I love the minimalistic art style though.
Vehicle physics are super hard to get right, so I'm super impressed with this entry! Great work :)