Following the success of its TDI and FSI engines, Volkswagen is launching the latest in a line of pioneering inventions with the introduction of TSI petrol technology.

FSI uses direct injection to improve combustion efficiency and hence reduce fuel consumption and emissions. Taking this further, TSI uses – for the first time ever – an FSI engine which is then dual-charged through a combination of an engine driven supercharger and an exhaust gas turbocharger arranged in series.

The driving characteristics of the new TSI engine are improved over those of the current FSI unit. The belt-driven supercharger operates at lower engine speeds, with the turbocharger coming in as the engine speed increases. The result of this is excellent driveability and performance throughout the range with no turbo lag and high maximum torque.

The new TSI engine has a capacity of 1.4-litres (1390 cc) and produces either 140 or 170 PS. The 170 PS version has the same peak power as a conventional 2.3-litre petrol unit but with 20 per cent lower fuel consumption, returning 38.2 mpg on the combined cycle. It also produces impressive torque of 177 lbs ft (240 Nm) from 1,750 through to 4,500 rpm.

The combination of these technologies enables a small capacity engine with a high compression ratio to cruise at part load on high gearing to combine dramatic performance with exceptional fuel consumption for a petrol engine.

At the same time, the Golf line-up will be joined by a new 2.0-litre TDI engine producing 170 PS – the most potent diesel-powered unit ever produced for a Golf.

A development of the popular 2.0-litre 140 PS TDI engine, this new powerplant uses Piezo electric elements to control precisely the fuel injection, thus maximising power output but minimising consumption and emissions. Emissions are further reduced by a maintenance-free particulate filter.

Maximum torque of 258 lbs ft (350 Nm) is available from 1,750 rpm. A top speed of 137 mph and 0-62 mph in just 8.2 seconds mean strong performance, yet combined consumption of 46.3 mpg guarantees little time and money spent at the pumps.

These new petrol and diesel engines have prompted a revision in the Golf line-up. The existing GT trim will be altered to look more like the GTI, gaining a new front grille, GT badges, 17" ‘ClassiX’ alloy wheels, lowered suspension (by 15 mm) and twin exhaust pipes. Both the 2.0-litre 140 and 170 PS TDI engines as well as the 1.4-litre 170 PS TSI petrol will be offered in GT trim. Prices will start at £17,995 for the 140 PS TDI; £19,095 for the 170 PS TDI; and £18,095 for the 170 PS TSI. Further down the range, the Sport trim will now be available with the 1.4-litre TSI 140 PS (£15,995), 2.0-litre 105 PS TDI (£16,025) and 2.0-litre 140 PS TDI (£17,320) units.

The revised Golf range will be available to order from 21 April.