Review

##vwgolf4.jpg --Right##A SPARKLING new power unit is poised to catapult Volkswagen to pole position in the crucial medium-size family class for diesel cars. Developing 150bhp, the ultimate rendition of the German company's long-serving four-cylinder, 1.9-litre unit promises to bring GTI-style progress to heavy-oil versions of the Golf and Bora.

Due to reach Britain next year, the engine is unique in achieving a fresh record power output in its sector - 79bhp per litre - and should allow VW to underline its dominance in several key European markets. Available immediately to domestic buyers, it will be introduced in Austria, Italy and France before reaching British and Irish showrooms.

Incorporating technology and changes proved out during the tough British Rally Championship series, the top-performing TDI unit gives the heavy-oil Golf the ability to storm up to the benchmark 62mph rate from rest in just 8.6 seconds. And it sweeps away any remnants of the old myth that diesel propulsion is sluggish and slow by zipping the car on to reach an equally impressive 134mph top speed. Details of when the new 'superturbo' diesel cars will be marketed in Britain are sketchy, but it is understood it could be 12 months before they will be put on sale.

However, vehicles equipped with another second-generation engine will soon be on offer to UK customers. Golf, Golf Estate and Bora models powered by a 100bhp turbodiesel unit are due to reach showrooms before the end of the year and will replace the present line-up of 90bhp models.

In January, the 100bhp unit is due to take over from the present 90bhp motor in the Passat and it is also to be offered as an option in the New Beetle.

Unprecedented efficiency allowing VW to claim it now produces a genuine GTI diesel comes from larger-diameter injection nozzles, a different intercooler mounted at the front of the car and a bigger turbocharger operating at up to 2.2 bar pressure.

In 100bhp form, both the Golf and Bora offer significantly better progress than their conventional direct injection predecessors. Helped by a variable turbine geometry turbocharger, the new engine provides greater torque at low revs and pulls away strongly from little more than idle speed in any ratio.

Well-suited to either car, it has good effortless acceleration and the tall gearing that allows quiet, effortless and economical motorway cruising. But the star performer is undoubtedly the 150bhp unit. Though it tends to be noisier under harsh acceleration, the engine sound has an eager, raw edge in keeping with its sporty nature and is not unpleasant.

Hugely entertaining to drive, these versions of the Golf and Bora pack sufficient power for wheelspin to be induced at will, even though they have electronic stability control as standard, and just a dab on the accelerator at anything less than 100mph sends them surging ahead.

In front-drive form, as they will be supplied for the UK market, the most rapid of compact diesels have massive safety reserves stemming from precise roadholding and balanced handling.

Offering dynamic travel that would have been thought impossible only a few years ago in this sector, they represent a technical triumph that delights the driver while also achieving high operating economy.

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