The exhaust system vents exhaust gases by way of a muffler, which helps reduce engine noise. The lubrication system keeps friction from wearing out moving parts. The engine uses relatively lightweight motors oils, and heavier weight oils and greases are used in the transmissions and wheel bearings. The cooling system prevents the engine from overheating, generally by means of a liquid coolant, although many engines are air-cooled. The suspension system comprises of coil or leaf springs and shock absorbers, and combines with the tires to cushion the vehicle from the shock caused by driving over irregular surfaces.
Tyres come in a variety of tread designs to provide traction in all driving conditions.
An automobile goes through a number of steps before it is ready to come on the roads. It involves a number of steps, like the manufacturing of engines and transmissions, the stamping of body parts, the procurement of batteries, tyres etc and culminating in the assembly of the vehicle on a production line. The body and the chassis are the usual lines. The stamped body parts are first welded together and painted, and items like the windows and instrument panel are installed. On the chassis line, meanwhile, the stamped body parts are first welded together and painted, and such items as windows and the instrument panel installed.