2021 Subaru WRX STI Performance

The WRX STI follows basically the same recipe Subaru has used since the very first WRX model was introduced in 1992. You take a powerful flat-four engine and turbo charge the heck out of it. In the current model, that results in 310 horsepower and 290 lb-ft from a displacement of 2.5 liters. That's enough for a 0 to 60 mph sprint in less than six seconds according to independent tests but launches are hardly a smooth experience as it requires clutch drops from high revs that are mechanically jarring.

The STI has a few inherent characteristics, like the unmistakable soundtrack of a flat-four engine, and the initial turbo lag followed by a massive shunt of power. There's no modern twin-scroll turbo trickery at play, which means you have to work the six-speed manual gearbox hard to keep the engine in its powerband.

The manual gearbox is the only transmission option available, so it's worth keeping in mind that this is a car that demands driver involvement. It's not like the outgoing Golf R, where you have the option of sitting back and letting it do all the work. The Subaru demands attention and engagement, which is exciting in a way but limits its appeal as an everyday car.

In 2019, Subaru made some subtle tweaks to the STI's engine. The air intake was revised, the pistons were strengthened and the ECU was remapped. The result was 310 hp and 290 lb-ft of torque. Still, the STI's engine feels old-school. Modern turbocharged engines mated to automatic gearboxes with eight gears or more have virtually eliminated turbo lag, so it's odd to get into a car where the lag remains so prominent. Once you get it going, and you manage to keep it in the powerband, it flies.

The six-speed manual gearbox is the only transmission option. It's a fantastic manual gearbox but it limits the day-to-day appeal of the STI. The STI wants you to work hard to get the most out of it, but it can be exhausting if you only want to get from one part of town to the other. The STI is at its best on an open road, with the turbo already boosting up a storm. In that setting, there's nothing quite like it. The question you have to ask yourself is whether this fairly limited reward is worth the effort of living with it on a day-to-day basis?

The WRX STI is nowhere near frugal. While modern turbocharged petrol powertrains have become known for being fuel efficient, this old 2.5-liter turbocharged flat-four will drink its way through a 15.9-gallon tank in just 286 miles. It has EPA-estimated figures of 16/22/18 mpg across the city/highway/combined cycles. To put that in perspective, the Mercedes-AMG C63 S, which has a 4.0-liter twin-turbo V8, has EPA-estimated figures of 17/26/21 mpg. You can expect those figures to drop even further when you regularly make use of its full performance potential.