Ford is offering approved engine performance upgrades for its Focus ST through five of its Ford Retail dealers.

The select Ford dealers will be able to tune the ST’s 2.5-litre Duratec ST engine from 223bhp to 258bhp through the Mountune Performance package for £1,120 which excludes fitting.

The upgrades carry a minimum of 12 months/12,000-mile dealer warranty up to a maximum of three years/36,000 miles.

The upgrade kit does not affect the vehicle warranty but customers will have to inform their insurance company.

Ford said there would be more Mountune performance packages available for other models in the Ford range later this year.

The first dealers to offer the upgrade will be:

• Dagenham Motors, Woodford, London
• Brunel Ford, Bristol
• Heartlands Ford, Birmingham
• Polar Ford, Warrington
• Polar Ford, Castleford