The powerplant develops 169bhp despite its small cubic capacity, thanks to a twin-charger system.
This incorporates an engine-driven supercharger and an exhaust gas-driven turbocharger in series, which produce 2.5bar maximum boost and give it the equivalent power output of a conventional 2.3-litre petrol engine but with 38.2mpg on the combined cycle and 175g/km CO2 emissions, according to VW.
It replaces the 150bhp 2.0 FSI engine previously in the Golf GT.
A spokesman says the carmaker acknowledges that many consumers have traditionally bought cars based on engine size so the small capacity could initially be a hurdle to overcome.
However, dealer staff have undergone product training to explain the technology used and the benefits it provides. “We’ve also deliberately not put 1.4 badging anywhere on the car for this reason,” he adds.
The 1.4 TSI engine is also available in 139bhp form in Golf Sport, Golf Plus and Touran and has completed durability tests to 300,000km.
VW is also developing TSI technology for smaller capacity engines.