In body-over-frame construction, the frame consists
of thick steel members. The chassis parts and the body
bolt to this frame. Also called full frame construction or
perimeter frame construction, this design is heavy but
strong. Body-over-frame construction is used on full-size
cars, vans, pickup trucks, and sport-utility vehicles
(SUVs). See Figure 1-3A.
With unibody construction, sheet metal body panels
are welded together to form the body and frame. Also
called space frame construction or unitized construction,
this is the most common type of configuration used to
build small and medium passenger cars. Unibody con-
struction reduces weight, improves fuel economy, and
has a high strength-to-weight ratio. However, unibody
vehicles are not as strong as those with body-over-frame
construction. See Figure 1-3B.
Body Types
Automobiles are available in several body types,
including the sedan, hardtop, convertible, hatchback, and
station wagon. In addition, the minivan, the sport-utility
vehicle, and the pickup truck have become increasingly
popular.
A sedan is a car that has front and back seats
and will carry four to six people. It has center body pil-
lars, or “B” pillars, between the front and rear doors,
Figure 1-4A. Both two-door and four-door sedans are
available.
4 Section 1 Introduction to Automotive Technology
Figure 1-4. Note the various vehicle body styles. A—Sedan. B—Convertible. C—Hatchback. D—Station wagon. E—Minivan.
F—Sport-utility vehicle. (Toyota, Ford, Honda, Mazda)
B
A
C
D
E
F