Power Transfer

Several processes have to happen in order for a vehicle to move.

Power Transfer Steps 
Fuel is stored as chemical energy in the gas tank.
Fuel is transported to the engine by a fuel pump.
Air-fuel mixture enters the engine.
Electrical energy is used to create a spark at the spark plug.
Combustion occurs, converting the chemical energy to kinetic energy. The piston moves linearly, reciprocating up and down or back and forth.
The reciprocating motion of the pistons is converted to rotary (circular) motion of the crankshaft.
The crankshaft’s rotary motion turns the transmission.
On front-wheel drive (FWD) vehicles, rotary motion is transferred through a transaxle (transmission and differential combined). From the transaxle, rotary power is moved through constant velocity (CV) shafts.

On rear-wheel drive (RWD) vehicles, rotary motion is transferred from the transmission through the drive shaft then to a differential and final drive assembly. In this situation, the differential changes the power flow 90° and allows the drive wheels to turn at different speeds when cornering. Power is transferred from the differential to axle shafts.

The axle shafts or CV shafts turn the wheels.
10 The rotary motion of the wheels converts to linear motion on the roadway.