A tilt test is a test for automotive safety used to make sure a car's center of gravity is safe enough for competition or use, and to check for fuel leaks. This testing is most commonly used for cars raced at events or displayed in experimental vehicle competitions, although major car manufacturers can also use tilt testing during the research and development phase while working on new models and designs. The test involves driving or rolling the vehicle onto a platform, strapping it down, and then tilting the platform to see how the car performs.
While being driven, it is anticipated that cars will tilt going around curves because of the way they are banked. If the car's fuel or other fluid systems leak, these can become a problem when the car is tilted and may expose the driver to unreasonable risk. If the center of gravity is wrong, the car may be prone to tipping over while cornering, a potentially very dangerous situation when a car is moving at high speeds. The tilt test is used to make sure a car meets basic performance standards.
One important phase of the tilt test happens when the car is tilted to around 30 degrees, where the fuel system will be checked for leaks. An inspector will evaluate the car, and may check for leaks and signs of strain with systems other than the fuel system. The car is then tilted to 60 degrees. If at least three tires remain in contact with the platform, it meets the standard for center of gravity. If the car starts to tip or only two tires remain in contact, it will fail the tilt test.
For competitions, the tilt test may be performed with the driver in the seat, strapped in and wearing all applicable safety gear. Competition vehicles for racing are engineered to function optimally at very precise weights. Tilt testing without the driver might result in skewed results. Drivers are monitored carefully while their vehicles are tilted and if the driver appears to be in danger, the test will be stopped. The car will also be disqualified on the grounds that failing the tilt test would make it unsafe to drive on the course.
Car manufacturers, as well as designers of cars for competition, can have a tilt table in their research and development facilities for testing cars as they are developed. This allows them to check on safety periodically, making adjustments as needed before the pressure of an official inspection is on. This is one among a large group of safety tests used to determine a car's fitness for driving and competition.