If the all-new 2015 Subaru WRX has taken a good thing and made it great, then this should be, well, greater. Meet the range-topping WRX STI, packing more power, a decidedly more aggressive ...

For STI shoppers looking for a little more luxury, a Limited model is once again offered, with a leather-trimmed interior, eight-way power driver’s seat, Harmon/Kardon sound system, and a moonroof.

Surprisingly, the old STI was not the king of Subaru's hill. That honor goes to the WRX Special Edition, which went on a diet and dropped its 60-mph sprint to 4.7 seconds and the quarter-mile ...

Active Torque Vectoring uses braking on the inside front wheel to tighten up your turns, as with other WRX models, but the STI also has a helical limited-slip front differential and Torsen limited ...

It's not often that a car gets less expensive and sportier at the same time. But that's exactly what has happened with the new Subaru WRX STI Special Edition. It costs $32,995, whereas a standard ...

Since 1983 the Torsen® differential has been employed in the powertrain of more than two-dozen sedans, SUVs, and military vehicles. This differential device is renowned for its unique high torque bias ...

To understand the benefits of a limited-slip differential, you have to understand the basic components involved in turning a car’s engine power into forward (or reverse) movement.