The huge success of the Zafira 1.6 CNG (Compressed Natural Gas) and the Astra Caravan 1.6 CNG has prompted Opel to include a third natural gas vehicle in its range. Opel's subsidiary OSV (Opel Special Vehicles) will present its prototype of the Combo Tour 1.6 CNG at the14th Auto Mobil International (AMI) in Leipzig (April 17 – 25, 2004). The prototype will be shown at the natural gas suppliers' association stand (Stand F32/Hall 3), and the market launch is expected in the second half
of 2005.
Like the Zafira 1.6 CNG and the Astra Caravan 1.6 CNG, which accounted for a market share of nearly 60 percent of Germany's natural gas passenger cars in 2003, the Combo 1.6 CNG has three gas tanks holding 19 kilograms or 110 liters of volume, as well as a
14 liter gasoline reserve tank. One advantage of this innovative monovalent plus concept is that the driver can switch over to gasoline supply directly from the cockpit when the gas tanks are empty and there is no natural gas station nearby. CNG-Combo's operating range then increases from 400 to around 550 kilometers. Thanks to its unique, space-saving underfloor gas tank system, the Combo 1.6 CNG offers as much room as the Combo models with gasoline or diesel engines with maximum
loading capacities between 2,695 and 3,050 liters.
In addition to its spaciousness, the Combo 1.6 CNG's economic efficiency is its greatest asset. Taking average fuel consumption of 5.3 kilograms of H-quality natural gas per
100 kilometers and the current price of 0.68 Euro per kilo of natural gas, fuel costs can be reduced by up to 30 percent compared to the diesel Combo or even 50 percent compared to the gasoline-fueled Combo.
Another advantage of driving natural gas cars is the fact that some 65 percent of all regional and local natural gas providers in Germany promote this environmentally friendly form of fuel. They either contribute an average of 1300 Euro to the purchase of a natural gas car or supply the car owner with an average of 1500 kilograms CNG fuel free of charge. Natural gas fuel is also tax-advantaged until 2020 – unlike gasoline and diesel. It is also environmentally friendlier, as natural gas
engines emit far fewer pollutants than conventional combustion engines. As a result, the Combo 1.6 CNG's CO 2 emission is only 140 grams per kilometer.
The 1.6 CNG engine is based on the popular 1.6-Liter ECOTEC gasoline engine and has power output of 71 kW (97 hp) at a maximum torque of 140 Newton meters. The engine was optimized for natural gas operation and has separate injection bank for each type of fuel. With 130 octane, natural gas is distinctly more knock resistant than gasoline. Opel focused on maximum natural gas operation efficiency and raised the compression ratio to 12.5:1. In spite of its economic efficiency, the Combo 1.6 CNG impresses with lively performance, a top speed of 166* km/h and a 0-100 sprint in 14* seconds (*preliminary data).
With a total capacity of 110 liters or 19 kilograms, the underfloor tanks allow a range of approximately 400 kilometers. The gasoline reserve tank increases operating range of the Combo 1.6 CNG to about 550 kilometers. Switching over from natural gas to gasoline operation simply requires the turn of a switch located on the center console or happens automatically when the natural gas supply is too low. The system simultaneously switches over to the corresponding pressure or gasoline gauge for the fuel in use. A universal gasoline filler neck enables refueling without an adapter in countries with different natural gas station norms, such as Italy. The Combo 1.6 CNG can also be fueled with biogas.
The Combo 1.6 CNG meets highest safety standards, too. The entire tank system is mounted to the underbody with steel retaining bands and the tanks are additionally protected by an underbody panelling. Each gas tank has its own valve and is made of high-strength steel, with stainless steel gas pipes.
The location of the gas tanks outside of the impact zone guarantees highest possible safety for passengers and environment. Moreover, natural gas is potentially safer than gasoline in case of accident.
If a leak were to occur, the natural gas would dissipate into the atmosphere because it is lighter than air, and at 650° Celsius its ignition temperature is substantially higher than that of gasoline. Drivers of a CNG-powered Opel model do not need to heed the signs in German parking garages prohibiting entry to gas-powered vehicles. Entrance is prohibited to gas-powered vehicles with fuel heavier than air, such as liquid gas. Due to high safety standards, the technical inspection association
in Germany (TÜV – Technischer Überwachungsverein) makes no differentiation between natural gas and conventional vehicles in mandatory general inspections, with the exception of requiring separate inspection of the gas tanks every ten years.
The entire gas tank assembly is installed in the series production models by Opel Special Vehicles GmbH (OSV) in Rüsselsheim. Founded in January 2000, this Adam Opel AG subsidiary currently employs 350 staff and has been manufacturing standard Opel natural gas models since 2002. Further OSV products include the sporty OPC models, the modification of public authority and special-purpose vehicles for police, driving schools and taxi cab companies as well as diverse customization of Opel standard models. More than 65,000 Opel modifications were completed by OSV GmbH in 2003.
The CNG models are part of Opel's threefold strategy to decrease carbon dioxide emissions to 140 grams per kilometer in its new vehicle fleet by 2008. The use of alternative fuels such as natural gas plays an important role in this strategy, in addition to optimizing proven technologies and developing ready for series production vehicles equipped with hydrogen energized fuel-cell propulsion systems.
OSV General Manager Stefan Schrahe states: “With the Combo 1.6 CNG we want to make our customers an offer no other manufacturer can match at this stage. Its innovative technology makes it an extremely clean and economical vehicle, with no limitations on everyday use or spaciousness.”
Text and photos courtesy of General Motors
