A chassis can also refer to the base upon which a car is built. All of the bits that deal with the cars
locomotion are in one way or another attached to the chassis, this includes the
engine,
suspension,
transmission and the
body. The chassis design decides the
rigidity of the vehicle and how it will ulitmatly be built.
The chassis can be built in many ways, each with its own unique benifts and disadvantages.
One of the oldest forms of chassis is the ladder frame, which much like it sounds, is built like a ladder. It has lost favor in car design, but is still used in trucks and large SUVs. It is also found in the Fox platform Ford Mustangs. Ladder frames provide decent chassis strength and are easily hand built but lack torsional rigidity due to their 2 dimensional design. They also tend to be overbuilt and cumbersome, adding significantly to the weight of the vehicle.
Most cars today have monocoque chassis, in which a shell, which sets the shape of the body also acts as the load bearing chassis. Monocoque construction is great for mass produced vehicles due to its low cost and suitability for robotic production. Monocoque vehicles also fare well in crash tests and have decent chassis rigidity. Steel monocoque chassis tend to be quite heavy and are next to impossible to use in small production runs. Most car manufacturers, from Pontiac to Porsche use steel monocoque chassis.
Tubular space frames are used in extremelylimited production run sports cars such as the Lamborghini Diablo, Mercedes-Benz 300SLR, and many Ferraris. space frames are also very common in professional and home-built dune buggies and sand rails. The space frame has the advantage of being extremely strong in every direction and space frames are extremely light for their strength. Despite these advantages, space frames are not seen in most cars due to their extreme complexity and costliness along with their large interior space engagement.
There are several other chassis designs but they are not very common in today's vehicles.