With all the focus, quite rightly, on Subaru’s excellent new BRZ, the company has decided to give the Impreza WRX STI a bit of a boost. Quite literally, by offering a new 340R power upgrade.

The 340R boasts 335bhp and 361lb-ft (490 Nm) of torque, an increase of 39bhp and 61lb-ft over the standard WRX STI. The 340R power upgrade, which adds £1,599 to the WRX STI’s list price, is available alongside the 320R (with 315bhp and 332lb-ft) which was launched in the UK last year.

If that doesn’t tempt you, Subaru are offering the WRX STI model during September for just £26,995 – down from £32,995. An additional finance offer means the STI can be financed at under £300 a month.

Both the 340R and 320R power upgrades can be applied retroactively without affecting a car’s warranty, although customers won’t benefit from the special price for a new car during September.

The 340R power upgrade features different ECU settings for the 2.5-litre horizontally-opposed, four-cylinder Boxer engine, while airflow has improved as a result of a new exhaust system, which also enhances the WRX STI’s unmistakeable exhaust note, with its classic Subaru burble.

Acceleration from zero to 60mph can now be despatched in 4.7 seconds, 0.5 seconds quicker than the standard WRX STI, with no change in the quoted fuel economy and CO2 emissions.

So, for the time being you could choose between a 335bhp Impreza WRX STI or a 197bhp BRZ for virtually the same price. Sounds like it’s a pretty good time to buy a performance Subaru.