Hybrids and electric vehicles may be the future at the Volkswagen Group, but the combustion engine will still dominate many years from now. For those in need of diesel-like fuel economy without the disadvantages of a TDI-powered car, VAG offers a decent number of vehicles powered by petrol engines that can run on compressed natural gas (CNG).
Following the launch of the SEAT Arona TGI and the updated Skoda Octavia G-TEC, the VW core brand is unveiling today revised versions of Polo TGI and the bigger Golf TGI. Powered by a 89-bhp 1.0-litre three-cylinder engine, the supermini has gained a third CNG tank carrying 16.5 litres of natural gas to increase the grand total to 91.5 litres. As per the new and more realistic Worldwide Harmonised Light Vehicle Test Procedure (WLTP), the supermini hatchback can now travel for up to 229 miles purely in CNG mode.
Here's another CNG car from Volkswagen Group:
As far as the Golf TGI is concerned, it’s been upgraded to a new 1.5-litre four-cylinder engine that needs 3.5 – 3.6 kg of natural gas for every 62 miles (100 kilometres) covered. The 128-bhp powertrain runs on the TGI Miller combustion process and makes use of a turbocharger benefitting from variable turbine geometry allowing more air to go into the cylinders. Compared to its predecessor, the Golf TGI can travel for an additional 50 miles on natural gas while slashing emissions to as low as 95 g/km.
VW points out the main advantages of purchasing a car that is CNG-friendly. Not only is it more fuel efficient than a regular petrol-fuelled car of the same size, but it cuts emissions by approximately 25 percent.
With the eighth-generation Golf right around the corner, this could very well be the last update VW is applying to the Mk7. Of course, we won’t have a problem with the folks from Wolfsburg if they’ll send off the current Golf with the much-hyped R420 version…
Volkswagen gives some gas with new TGI models
Volkswagen has completely overhauled its natural gas models and is equipping its Polo and Golf TGI3 with a third natural gas tank. This allows the Polo TGI2 to now travel up to 60 kilometres further in pure CNG mode than its predecessor. The gain in range in the Golf TGI is up to 80 kilometres. In the Golf, a new 1.5 litre TGI four-cylinder engine with 96 kW / 130 PS ensures that none of the driving pleasure is lost. Driving with natural gas significantly reduces CO2 emissions because the combustion of CNG generally produces less CO2. An even better CO2 balance can be achieved by fuelling with biomethane or e-gas. Biomethane is extracted from plant residues; e-gas is produced from surplus green energy (power-to-gas), which are added to the fuels.
Anyone who already drives a CNG vehicle (CNG = compressed natural gas) also benefits from comparably low fuel prices in many countries. In Germany, for example, the cost saving compared to a diesel vehicle is currently 20 per cent, or 40 per cent compared to a petrol vehicle. Understandably, drivers of natural gas vehicles only want to use petrol in exceptional cases. Volkswagen has therefore equipped its natural gas models of the Polo TGI2 and Golf TGI3 with a third natural gas tank made of specially coated, high-strength steel. The Golf’s tank has a volume of 23 litres and increases the total CNG tank volume to 115 litres, or 17.3 kg respectively, which offers a range of up to 422 kilometres in WLTP.
On the Polo with 1.0 three-cylinder engine (66 kW / 90 PS)2 the additional tank carries 16.5 litres and extends the natural gas storage to 91.5 litres in total, or 13.8 kg respectively, meaning that the Polo can travel up to 368 kilometres on CNG in WLTP. As a back-up, both models come with a petrol tank – albeit a much smaller version.
For improved driving dynamics and efficiency, the Golf TGI3 comes with a new 1.5 litre four-cylinder engine, which is powerful, efficiency and environmentally friendly. Proof of this comes from its fuel consumption of just 3.6 kg – 3.5 kg natural gas over 100 kilometres, and CO2emissions of just 98–95 g/km. The new 1.5-litre TGI engine in the Golf uses the innovative TGI Miller combustion process with a high compression ratio of 12.5:1, to increase efficiency and decrease CO2 emissions. A turbocharger with variable turbine geometry increases the boost pressure, adding more air into the cylinders. This allows the 1.5-litre TGI engine to accelerate powerfully at any time from low speeds.
Driving on natural gas is not only good for your wallet, it is also good for the environment. Compared to petrol or diesel, natural gas contains a significantly higher amount of energy and a lower carbon fraction. This means that driving in CNG mode produces around 25 per cent fewer CO2 emissions than with petrol. What is more, natural gas generally combusts with less emissions than petrol or diesel. The exhaust gas contains significantly less carbon monoxide and nitrous oxide (NOx), while the fraction of soot or fine particles is minimal.