Vauxhall unveils an all-new high-tech 1.0-litre three–cylinder petrol engine at next month’s Frankfurt International Motor Show, ahead of its debut in the ADAM city car next year.

The 1.0-litre turbo petrol, known as SGE (small gasoline engine), represents a new benchmark for refinement in three-cylinder engines, with noise, vibration and harshness (NVH) characteristics superior to many four cylinder units.

Developing 115PS, the pocket powerhouse delivers generous low-end torque of 166Nm all the way from 1,800 to 4,700rpm, belying its small size.

The 1.0-litre spark ignition direct injection (SIDI) turbo generates more torque throughout its operating range than equally powerful, higher displacement engines, while fuel efficiency is improved by 20 per cent compared with the current 1.6-litre naturally aspirated unit that powers the Astra.

Set to appear first in the stylish ADAM next year with an all-new six-speed gearbox, the 12-valve, 1.0-litre turbo is the first in a new, modular family of three and four-cylinder Vauxhall petrol engines up to 1.6-litres.

State-of-the-art technologies such as direct injection, continuously variable valve timing, and a lightweight aluminium cylinder-block, are key to the engine’s efficiency. Vauxhall expects the new engine family to deliver impressive fuel economy and CO2 emissions significantly lower than 100g/km.

The 1.0 SIDI Turbo is mated to an all-new, six-speed manual gearbox specially designed for medium torque applications. With a dry weight of only 37kg, it is about 30 per cent lighter than its current counterpart. It is also extremely compact, measuring just 375mm along its axis.