Natural gas vehicles are popular in Europe with nearly 100,000 on German roads. Italy has about 800,000 due to a favorable tax advantage plus rebates on new car purchases, exemptions from certain traffic rules, and an extensive, subsidized natural gas station network. Most European automakers offer at least one compressed natural gas (CNG) model. Volkswagen offers the Caddy 2.0-liter EcoFuel, extended Caddy Maxi 2.0-liter EcoFuel, Touran 1.4-liter TSI EcoFuel, Passat and Passat Estate 1.4-liter TSI EcoFuel, and now the eco up! Next year, these will be joined by an EcoFuel version of the VW Golf.
The eco up! features Volkswagen’s newly developed three-cylinder, 1.0-liter gasoline engine. Here, the lightweight, aluminum 12-valve engine was designed to operate on natural gas, but can run on unleaded premium gasoline as well. Driving on natural gas, it produces 67 horsepower and 66 lb-ft torque, a combination that motivates this four-place urban car from zero to 60 mph in about 16 seconds with a 102 mph top speed.
Natural gas is stored in two subfloor tanks near the rear axle. This location means they don’t reduce useable space, although they do displace the normal spare tire recess. The eco up! has a total range of 373 miles – 236 miles on natural gas and another 137 miles on the reserve gasoline tank.
According to Volkswagen, the new eco up! is currently the world’s most fuel-efficient natural gas passenger car with consumption of just 2.9 kg of natural gas per 100 kilometers. This equates to roughly 56 U.S. mpg. Helping achieve this fuel efficiency are low vehicle weight, good aerodynamics, low rolling resistance tires, BlueMotion Technologies Stop/Start system, and regenerative braking.
A major benefit for natural gas cars like the eco up! is that they are not limited to just natural gas, but can also operate on alternative fuels such as renewable biomethane. When produced from straw, animal and biological wastes, or plant byproducts, biomethane does not compete with food crops, which is currently the case with biodiesel and ethanol. Biomethane is also CO2-neutral since the car only emits as much CO2 during combustion as is absorbed by feedstock plants while growing. Today, biomethane is blended with traditional natural gas at a quarter of Germany’s natural gas stations and is available as pure biomethane at about 100 stations.
Natural gas vehicles can additionally run on e-gas, also known as ‘power-to-gas.’ Electricity produced by wind or solar power is used to produce hydrogen by electrolysis, and in a second step the hydrogen is converted to methane to be used in vehicles. As fuel cell vehicles become economically practical, the hydrogen can be used directly in vehicles. Importantly, e-gas represents a way to store overcapacities from renewable sources in the form of methane or hydrogen for use in vehicles or electrical generation plants when wind isn’t blowing or the sun isn’t shining.