There's an elite group of Ford test driver engineers stationed in Dearborn, Michigan. One of their many tasks is to strap into a specially developed Mustang race car with over 500 hp and run it around on a test track. Ford says these engineer drivers are its tier-four test drivers. Only about 20 exist out of a total of 10,000 or so test driver engineers at Ford. That's because only 20 have completed the rigorous training and certification required to move up from tier-three.

"Not only are these elite Ford Performance drivers the best of the best, many of their peers believe they have the company's coolest jobs in that they get to bring their enthusiasm, technical know-how and racing expertise to work every day," said Ben Maher, technical specialist, global driver safety and leader of Ford's internal driver qualification program.

Maher and his team at Ford Performance have built the Mustang FP350S track car, complete with a full roll cage and second seat (for a fellow engineer) as well as a 50-channel data acquisition system. This system enables drivers to gauge their performance driving skills down to the finest of details. Factors such as steering wheel angle, brake pressure, and even transition time between throttle and brake pedal are taken into account. "The performance limits of the FP350S are so high that to master it, vehicle control needs to become automatic," said Maher.

"High-limit driving becomes intuitive to the point that when one of these drivers gets in another vehicle, they are freed up to observe more of what's happening at the vehicle level." Of course, the knowledge these tier-four engineer drivers learn behind the wheel at the track often translate into new and better features for future performance road cars.