Ford’s Focus ST is set to lose a cylinder and 500cc of swept capacity as it attempts to survive in an emissions-strangled performance car market post-2012. The company’s popular three and five-door performance hatches have long been a favourite with petrolheads burdened by burgeoning family responsibilities.A combination of the ST’s spacious cabin dimensions and its characteristic five-cylinder turbo engine (not to mention the neat, multi-link rear suspension-aided agility) make it the perfect family man's hot hatch. Unsurprisingly, news of the 2.5-litre, Volvo-based engine’s demise was met with derision when announced earlier in 2010To placate fans of the ST nameplate, Ford has released images and details of the next-generation Focus hot hatch - set to feature smaller capacity EcoBoost power and a host of detail changes, inside and out.Subtle styling changesAlthough the car Ford will display at the Paris auto show during the first weekend of October is being billed as a design study, it will essentially galvanise into a production version of the new ST – make no mistake. Styling sees a radical new nose, featuring an oversized grille - sure to be the new car's most contentious exterior detailing upgrade. From the rear three-quarter view, the ST's most pronounced change is in the stylised tail lights which replace the Focus hatchback’s traditional thin-strip rear illumination. A peculiar new exhaust end treatment, mounted in the centre of the bumper (featuring a twin joined-hexagon design), will probably be deleted for road-going versions of the new ST. Although Ford is coy about engineering details of the next-generation Focus hot hatch, it promises the new car will in no way hurt the ST brand’s dynamic reputation. Four-cylinder STST traditionalists will surely miss the 2.5 five-cylinder unit, an engine that has proved eminently tuneable and which roared a rather unique acoustic signature. Replacing it will be Ford’s new EcoBoost two-litre, four-cylinder producing 186kW – an improvement of 20kW over the current ST. Being both smaller in capacity and featuring direct-injection, the new ST’s EcoBoost engine should ensure a 10-20% reduction in fuel consumption. Dynamically, Ford’s excellent dry-clutch Powershift six-speed DCT transmission should become available too. This dual-pedal option should greatly enhance the ST’s appeal, especially as it has traditionally only driven via a six-speed manual transmission, great for heel-and-toeing but no fun in a heavily trafficked urban environment.The ST showcar trimmed for its Paris motor show debut in three weeks also marks a cabin redesign (finally) sporting a new four-spoked steering wheel and improved fascia – the latter gaining a large infotainment control and display interface. Ford’s promised its third-generation ST will go on sale in all global markets at the beginning of 2012. A break in tradition will see Ford not offering its new ST in three-door configuration come 2012.Wheels24 will be at the Paris show to bring you the latest news - direct.