Bottom of the screen — tap the side you want, or slide. It changes lane the moment you touch.
Top — hold for the bottom and back thrusters. The tank is six seconds. When the flame turns hot, let go and it cools.
Jump roll — double-tap the top on the side opposite the car. It pops up, the side thruster fires, and the car rolls across one lane.
Tilt — turn it on from the menu. Lean forward to go faster, back to slow down, and tip sideways to steer. A hard tip is the jump roll.