What is a tram gauge primarily used for?

A tram gauge is primarily used to measure vehicle control points accurately, which is critical in ensuring that alignment and suspension settings meet the necessary specifications for optimal performance. This tool helps technicians confirm that the positions of critical components such as wheels, axles, and control arms are correctly aligned, maintaining the vehicle's stability and handling characteristics.

By focusing on control points, the tram gauge aids in diagnosing any structural deformities that may affect performance or safety. It is especially useful when working on vehicles that may have been involved in collisions or have experienced suspension issues, helping to restore them to their factory specifications.

The other options relate to different aspects of vehicle maintenance that do not directly involve the precise measurement of control points. For example, measuring impact force pertains to the analysis of collision damage, calculating fuel efficiency involves assessing engine and drive train performance, and determining weight distribution pertains to load management rather than the alignment and control geometry central to what a tram gauge assesses.