The eighth-generation Volkswagen Golf gains a natural gas-powered addition to its line-up with the debut of the Golf TGI, powered by a 1.5 litre inline-four cylinder Miller cycle bi-fuel engine that primarily runs on compressed natural gas (CNG), but which can also run on petrol when required. Here, the CNG engine produces 130 PS and 200 Nm of torque.

The Golf TGI’s three compressed natural gas tanks totalling 115 litres (17.3 kg) are integrated into the hatchback’s underbody. Rated for consumption at up to 4.1 kg of CNG per 100 km and CO2 emissions of 111 g/km on the WLTP test cycle, this permits a maximum fuel range of 400 km when running purely on CNG. A nine-litre petrol tank serves as a back-up if the car’s natural gas stores have been depleted.

The Golf TGI achieves low carbon emissions thanks to the efficiency of the Miller combustion cycle and the compression ratio of 12.5:1, according to Volkswagen, while a variable turbine geometry turbocharger increases the charge air pressure and improves acceleration from low engine speeds, says Volkswagen.

Refuelling with biomethane or or e-gas offers an even better carbon balance, says Volkswagen; biomethane is obtained from waste plant matter, while e-gas is produced from excess green electricity, it says. On top of producing lower emissions than petrol or diesel, exhaust gases from natural gas combustion also contains significantly less carbon monoxide and nitrogen oxides, and soot particulate output is also minimal.

The order books have opened in Europe for the bi-fuel capable Golf TGI. Meanwhile, at the performance end of the Golf scale, the Mk8 Golf R has been slated for arrival on November 4, and the forthcoming AWD hot hatch has been indicated to boast 333 PS from the latest iteration of the automaker’s 2.0 litre inline-four turbocharged petrol engine.