Ford tuning specialist Mountune has developed its most powerful tuning upgrade yet for the Fiesta ST, raising the output of the hot hatch to 232bhp.

The firm’s new m235 kit, which costs £575 including VAT, offers an extra 10bhp from the previous M225 upgrade and gives the 1.5-litre turbocharged three-cylinder engine an extra 35bhp from unmodified versions. It also boosts the Fiesta’s peak torque to 258lb ft, compared with the official 214lb ft of the standard version.

Alec Pell-Johnson, Mountune’s performance chief, claimed the kit “delivers both significant performance and driver enjoyment”.

As well as upgrading the output of the Fiesta ST engine, the modifications include developments to boost usability and performance, while ensuring the car retains the feel of an official manufacturer model. No-limit shift optimisation is included as part of the kit calibration, which combines with the firm’s established enhanced exhaust overrun function.