1.10. Vehicle Design Considerations
Design Objective. The first thing a manufacturer must consider is the specific job the
automobile should perform. Based on the requirements, different types of automobiles have
been designed-such as, trucks, buses, cars, trailers, racing cars etc.
Design Parameters. The designer of an automobile must consider the maximum required
acceleration, speed, economy, load to be carried, ride and handling characteristics, size etc., that
are expected from the vehicle. The maximum limits of these features are called the design
parameters. A finished automobile is a blend of all these components, one feature traded off
against another, to produce the final product.
Durability. Each part of the vehicle has a specific design life which takes into account its
operating load, speed, temperature, lubrication etc. Life of all the components together decides
the time period the vehicle should operate before major service is required.
Cost. One of the best selling points is a low price. Therefore, one of the major design
objectives is to lower the price without compromising the design parameters. In some cases, a
large reduction in costs can be accomplished with only a slight compromise in a design objective.
The cost reduction is also possible by changing the manufacturing method or by using cheaper
materials like fibreglass, plastic etc.
Many features of the product are the result of the engineer’s preference, which are usually
based upon the previous satisfactory performance of the design. There is a tendency to continue
those features until they become uneconomical or unpopular, or until new engineering manage-
ment takes over.