The torque-vectoring differential, cleverly called TVD by Lexus, is optional on the RC F, while a Torsen limited-slip differential comes standard. That makes the RC F the perfect test bed for our examination.

The torque-vectoring differential built a convincing case from the beginning. On the skidpad, the standard RC F loses cornering grip at its front tires first, while the TVD-equipped car circles with restrained but consistent oversteer. By holding understeer at bay, the torque-vectoring car achieved lateral grip of 0.94 g, and improvement of 0.03 g on the Torsen-equipped car. At the same time, the TVD reduced the average steering angle from 135 degrees to 99. That's the difference between awkwardly crossing your wheel-gripping lower hand over your chest or holding it comfortably at the six-o'clock position.

There's no question that torque vectoring improves objective performance, yet the strongest selling point for this differential is how the car feels from behind the wheel. Whether it's at the limit on the track or winding down country roads, torque vectoring makes the car livelier and more controllable. Without it, limit cornering is a trying exercise in traction management, load transfer, and other subtle variables. The torque-vectoring differential feels like a subtle push from behind. Turn the wheel and the car dives in so eagerly and effortlessly that you'll want to attribute its behavior to magnetic forces or supernatural powers. Or, you might just tell passengers that it's all due to your peerless driving technique. And isn't that worth the money?