Thanks to a supplementary engine control system developed by Siemens, gasoline engines can now run on either gasoline or natural gas. Until recently, natural-gas-powered cars had the disadvantage that natural gas filling stations are few and far between. The new control system allows motorists to enjoy the benefits of the cost-efficient and environmentally-friendly fuel natural gas without loosing the independence offered by a conventional gasoline engine.

The new system from automotive supplier Siemens VDO is suited for all vehicle classes. Cars equipped with the system generally use natural gas as their main fuel. When the natural gas tank is empty, motorists can switch to gasoline operation without impairing the vehicle’s handling properties. The Mercedes E 200 Kompressor already is equipped with this control system as standard.

The supplementary control system can be inexpensively installed into gasoline-powered cars. All that is required is a second control unit for natural gas operation. This unit regulates the fuel changeover, receives the signals from the sensors and controls the gas injection and shut-off valves. The existing engine control system for the gasoline engine remains intact, requiring only a change to the software. In addition, a central information display panel is installed into the car to keep the driver informed of the current mode of operation and the amount of fuel left in the tanks.

Around 1.5 million automobiles worldwide run on environmentally-friendly natural gas. Compared to gasoline, natural gas produces up to 75 percent less carbon monoxide and up to 25 percent less carbon dioxide during combustion. Most European motorists will also find the low fuel costs appealing, as a kilogram of natural gas currently costs about 70 euro cents, making it substantially less expensive than premium gasoline. (IN 2005.06.6)