While the horsepower wars may or may not be over, the efficiency wars are just shifting into high gear, with every carmaker on the planet searching for ways to get more power for less fuel. Volkswagen is well-positioned to break new ground in the segment, and it has unveiled a pair of new engines at this year's Vienna Motor Symposium.

Based around VW's proven TSI and TDI technologies, the 1.2L petrol and 1.6L diesel engines promise to deliver the driving experience of bigger engines while drinking less at the pump - and without the expense and complication of a hybrid drive system.

"The potential of internal combustion engines is far from exhausted," said Dr Jens Hadler, VW's head of engine development. Both engines are slated to slot into the new Golf and Polo.

The 1.2L turbo petrol unit generates 105hp (78kW) while its bigger brother, the 1.6L TDI comes in 90hp and 105hp (67kW and 78kW) flavors for the Golf and a 75hp (56kW) variant that's limited to the Polo only, all while meeting the EU's Bin 5 emissions standards. The 1.2L engine is modeled on VW's award-winning 1.4L TSI unit.

Either engine can be combined with VW's six-speed manual or its slick-shifting seven-speed DSG dual-clutch unit. The 1.2L engine generates a healthy 129lb-ft of torque from 1,500rpm, meaning it should prove peppy enough in the small Polo and Golf.

VW says the 1.6L TDI's modular design makes it the basis for all future four-cylinder diesels from the company. Both engines will be available in both the Polo and Golf later this year.

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