Subaru is offering free performance upgrades for its iconic Impreza WRX and STi Type-UK, raising power to 265 and 305 PS respectively.

The deal covers the three-month period of May, June and July – or while stocks last – and is worth £1,995 for the STi and £1,600 on the WRX.

The Prodrive-developed Performance Packs are fitted by the dealer after registration and carry the full Subaru three year/60,000 mile warranty.

It means the Impreza WRX STi Type-UK sees its power rise to 305 PS and torque leap from 253 lb.ft to 299 lb.ft resulting in a 0-60 mph time of 4.6 seconds and 0-100 mph in 12.2 seconds. Top speed is in excess of 155 mph.

Meanwhile, the standard WRX – available in both saloon and 5-door bodystyles – now has 265 PS and 257 lb.ft of torque. The 0-60 mph time is reduced from an already rapid 5.6 seconds to 4.8 seconds with 100 mph coming up in 14.1 seconds instead of 15.9 seconds.

Both Prodrive Performance Packs include a reprogrammed Electronic Control Unit (ECU) and free-flow exhaust system with a large single rear tailpipe.

The Impreza WRX saloon costs £20,300 with the 5-door at £20,800 while the WRX STi Type-UK is £26,400 (all prices On-The-Road).