October 18, 2000

Zafira 1.6 16V CNG

Compact Van Fueled by Natural Gas

Opel presents concept for environmentally compatible mobility

Rüsselsheim. Opel has developed an engineering study of the Zafira compact van which runs on compressed natural gas (CNG). The Zafira 1.6 16V CNG is equipped with a monovalent powertrain that has been optimized for natural gas, with a power output of 74 kW (100 hp) and maximum torque of 150 Newton meters at 3800 rpm. The top speed is 172 km/h.

As well as its high environmental compatibility, natural gas is exceptionally economical. At a current price on the German market of around DM 1.10 per kilogram for natural gas and consumption of 5.5 kilograms per 100 kilometers, the owner of a Zafira 1.6 16V CNG would pay only about 6 pfennigs per kilometer in fuel costs compared to about 17 pfennigs for the already economical gasoline-fueled Zafira 1.6 16V, or 11 pfennigs for the Zafira 2.0 DI 16V diesel.

No Restrictions on Performance, Space or Safety

For use in the CNG Zafira, the Opel engineers modified the ECOTEC power unit from the Zafira 1.6 16V, especially the fuel injection system and the pistons. The four tanks beneath the floor, with a total capacity of 120 liters, allow an operating range of 400 kilometers. In terms of performance, space and payload, this version of the Zafira demands no concessions. Even with natural gas as the fuel, the compact van remains a full seven-seater.

The Zafira's designers had a CNG version in mind from the very start. The compact torsion beam rear suspension provides ample space for the four gas tanks. A stable built-in frame guarantees the crash worthiness of these pressurized containers, in which the natural gas is stored at 200 bar. As the gas is lighter than air, it cannot settle on the road surface or the floor of a building in the event of a leak or after a serious accident. Unlike liquefied gas vehicles, CNG automobiles such as the Zafira can therefore be parked in multi-storey car parks or garages.

Tax Concessions until 2009

The purchase of natural gas vehicles earns tax concessions in all countries of the European Union until 2009. This offers buyers of CNG fueled cars more long-term planning security than buyers of any other kind of vehicle. By far the most important market for natural gas automobiles is Italy, where about 300,000 CNG vehicles are registered at the moment.

Natural Gas Benefits the Environment

The energy content of a kilogram of natural gas corresponds to that of about 1.5 liters of premium gasoline. The environmental characteristics of the monovalent natural gas engine are also positive. The high anti-knock properties of natural gas (130 octane compared to the 95 octane of premium grade gasoline) permit a higher compression ratio (13:1) and thus improved engine efficiency. CO₂ emissions are reduced by about 30 percent. In addition, there are lower emissions of carbon monoxide and nitrogen oxides than from gasoline or diesel engines. Natural gas is also almost devoid of sulfur and burns without generating soot. The stringent Euro 4 emission limits, which do not come into force until 2005, are fulfilled without difficulty.

Another benefit for both the environment and the owner: the oil change intervals can be extended as the engine oil is no longer enriched with suspended particles from the fuel. Natural gas also requires no additives whatsoever and refinement is unnecessary.

As long as the natural gas supply network remains sparse in most European countries, the use of this environmentally compatible technology will remain limited. Take Germany, for example: in this country with the largest population in Western Europe there are presently only about 150 natural gas filling stations open to the public, the majority of these on the premises of gas supply companies. "Opel is therefore calling for a rapid expansion of the natural gas infrastructure", says Hans H. Demant, Executive Director of the Opel International Technical Development Center (ITDC). "Only then can this environmentally friendly fuel get the widespread use it deserves."

Limited Production with Reserve Gasoline-Tank Planned

To counteract the drawbacks of insufficient fuel supplies, Opel engineers are also working on a monovalent version of the CNG Zafira with a 15-liter reserve gasoline tank. Starting in summer 2001, Opel Special Vehicles (OSV) will put a limited series of this conversion into production. In this specification the range will exceed 400 km. In contrast to similar vehicle concepts, the engine will be designed to reach its optimum output when fueled by natural gas. Power is reduced by around 20 percent when the engine runs on gasoline.

This version of the Zafira 1.6 16V CNG will also be a full seven-seater. Opel is aiming this car in particular at the Italian market, where the company forecasts mid-term annual sales of up to 8000 CNG vehicles. Opel also wants to offer this alternative fuel technology to customers with high environmental awareness in countries like Germany, since – as Hans Demant says – "CNG power is the cleanest kind of combustion engine on the market at the moment."