This model retains the same engine as the previous generation STI, which is a 2.5-liter EJ257

with dual AVCS however with modifications to the ECU which have

increased fuel economy slightly, and has given a 6 kW boost in power to

227 kW (305 HP). Torque, however, has dropped from 407Nm to 394Nm at

4,000 RPM and top speed is now 160 mph (258 km/h).

There are also

reports that along with the ECU changes, the rev limit was raised to

7,100 rpm to support the power increase at the upper rev range to

support a stronger top end.

It also retains a hydraulic power steering system as opposed to the

WRX's new electric-assisted rack. The steering rack was changed to a

quicker 13:1 ratio, as used in the Japan delivered vehicles, as opposed

to the 15:1 ratio of the previous models. Also, the 2.0-liter EJ207 that is standard for Japanese STIs was retained specifically for the Japanese market in the new 2015 WRX STI.

A sound tube device, also seen on the BRZ,

has also been fitted to the air intake system to channel certain

induction and turbo frequencies into the cabin, reports show this is

only fitted to vehicles in some markets. In Europe, Australia, Canada

and Japan, the STI is available with and without the wing. Starting in

2016 the US version of the limited STI was also made available with or

without the wing.

In 2013, British rally champion Mark Higgins lapped the Isle of Man TT course in 17 minutes, 35.139 seconds.

In

2015 Subaru released the WRX STI Launch Edition that came in World

Rally Blue Pearl exterior paint combined with gold-painted, 18-inch, BBS alloy wheels. Only 1000 Launch Editions were released in North America.

In

2015 Subaru released the WRX STI S207, limited to 400 units sold only

for the Japanese market. The S207 used the 2 liter EJ20 engine which was

tuned to 328 PS (323.5 hp, 241 kW) and 318 lb.-ft. of torque (431 Nm).

Upgrades also include a quicker-ratio 11-to-1 steering rack (compared to

13-to-1 for the stock unit). STI-spec Recaro front bucket seats, Bilstein's adjustable DampMatic II front suspension, and drilled rotors clamped by Brembo

monoblock six-piston front calipers and four-pot rear calipers. Up to

200 of the units could be equipped with the NBR Challenge Package, which

features a carbon-fibre wing and a badge commemorating Subaru's class

victory at the 2015 Nürburgring 24 Hours.

In 2016 Subaru released

the WRX STI Hyper Blue special edition series, with production limited

to 700 units for the United States. The new color covers the outside,

and it is also offset with gloss black 18-inch BBS

wheels, badges and mirror caps. Blue stitching brings the color into

the interior, and Subaru's seven-inch navigation system with a

nine-speaker stereo is standard for this version. In Australia, Subaru

announced the WRX Premium Hyper Blue special edition with the CVT

automatic will be limited to 200 units targeted to customers, and WRX

STI Premium with the six-speed gearbox will be limited to just 50 units.

In 2013, the Impreza won the IIHS Top Safety Pick+ award. In 2014, the car won the National Business Review Sports Car of the year award in New Zealand.