THEY carry the same 'ST' badge, but these are two very different cars. The new Focus ST170 and Mondeo ST220 have been developed for performance and honed to offer two very different driving experiences.

ST is Ford's badge which stands for Sport Technologies, and brings performance in a very accessible car.

You might think that this is a relatively minority sector, but overall, around a quarter of all sales of small family cars last year were performance or sporting derivatives.

So as the performance version of one of the UK's top sellers, the Focus ST170 is a very important model.

Ford's plan is to take models which they say (as you might expect) already excel in their respective categories, and add a spark of enthusiast passion.

Martin Leach, vice president of Ford of Europe, says the ST cars are the start of a plan to hit the performance car business on as many fronts as possible.

A more aggressive performance is embodied in the Ford RS (Rallye Sport) brand.

The first new-era RS vehicle will also be introduced this year the Focus RS, an all-out 220PS performance car inspired by Ford's Focus WRC World Rally Car driven by Colin McRae.

The two levels of performance technology will clearly appeal to different enthusiasts the RS to real performance purists and the STs to a broader group of enthusiasts who want to enjoy spirited driving, but with all the practicality and dependability of the mainstream model.

The ST Focus, priced at £15,995, and Mondeo (price not yet announced) are based clearly on their original vehicles.

The ST170, which went on sale in March, is available in both three-door and five-door form, with an estate coming this summer.

At its heart is a tuned version of the standard 130PS 2.0-litre Duratec engine, upped to produce 170PS at 7000rpm.

With a six-speed manual gearbox, this allows the Focus to achieve 0-60mph in 7.9 seconds, and a top speed of 134mph. But it is the more refined driving experience that makes the ST170 special.

It becomes a highly balanced performance car that is exciting to drive but refined, understated, and practical to own.

People buy horsepower, but what counts is torque. "That's what you really feel, how well the engine pulls, throughout the speed range," said Bernard Steeples, in charge of the car's development.

The Mondeo-based ST220 goes on sale this month, and whether as a four-door, five door or estate, Ford says it combines the performance of a sports saloon with the luxury of a grand tourer. With a 220PS 3.0-litre V6 engine, it brings "a high level of standard equipment along with safety and luxury".

Among the features are ABS, ESP and 'Intelligent Protection System', and a unique luxury interior with heated Recaro leather front seats, and satellite navigation.

Ford's marketing boss Keith Kershaw says: "The Mondeo ST220 is a grand tourer for customers who appreciate performance but demand the highest levels of safety and luxury."