Testing and Inspection Phase

Testing is done at all levels of a vehicle'’s design and construction. Individual components and their materials are tested to assess interaction with other components and for durability. Designs are tested for feasibility and cost effectiveness. Tools and assembly systems are tested for consistency and accuracy. But no amount of early testing eliminates the need for testing and inspection on the completed product.

Naturally, many of the same computer modeling programs and simulations that are used on the vehicle as a whole can be used on an individual component. But once the vehicle assembly is completed, testing is taken to a new level. Engineers take the vehicles to proving grounds, areas designed to demonstrate that the automotive technology works reliably even in extreme conditions and on a variety of road surfaces. There are sections designed to simulate road hazards like potholes, and areas of standing water to test hydroplaning responses. There are inclines and declines, straight-aways, banked curves, winding roads, and tracks laid out with a variety of road surfaces such as sand, gravel, and concrete. These facilities really test the vehicle as a whole and in a variety of areas.

Tires and powertrains are judged on how well they hold up over a period of mileage accumulation. The body of the vehicle is subjected to corrosive conditions to simulate the durability of the materials during a lifetime of even the harshest use. The steering mechanism is evaluated for stability and responsiveness. Another important item on the inspection checklist is the completed vehicle's vibration levels.

Everything from the fuel injection pump to the instrument panel, from the seat to the air bags, will undergo extensive vibration testing. Vibration testing is not merely about comfort and noise levels – though obviously such irritations can be detrimental and should be eliminated – but they are also a safety and performance issue. With components assembled so tightly, vibration at what we might think of as minor levels can determine whether a system succeeds or fails under various driving conditions. If components are not sitting precisely as they should, they'll move, shake, and rub against other components. That increases the likelihood of wear and tear on hoses, wires, and canisters, which can result in failures like coolant leaks and electrical shorts.

The tests are sweeping and comprehensive: each system and part – electrical systems, brakes, safety features, windows, heating, air conditioning, ventilation – is examined both individually and then again as an integrated part of the whole.