Opel Zafira Tourer 1.6 CNG Turbo ecoFLEX

Shortly after the Zafira Tourer’s world premiere at the 64th Frankfurt Motor Show, Opel is broadening the spectrum of its new compact monocab with highly efficient and environmentally friendly alternative propulsion.

In January 2012, the new natural gas ecoFLEX version with a best-in-class CNG range of up to 530 km – well beyond the 500 km mark – will be added to the powertrain portfolio of Opel’s flexibility master. Like the previous model, the Zafira Tourer features Opel’s monovalentPlus system and has a 14 litre gasoline reserve, giving it an extra 150 km range.

The Zafira Tourer 1.6 CNG (Compressed Natural Gas) Turbo ecoFLEX has 110 kW/150 hp, 210 Nm of torque and reaches a top speed of 200 km/h. The vehicle only uses 4.7 kilograms (7.2 m3) of natural gas per 100 kilometers in the combined cycle which is at least 6% better than the predecessor Zafira CNG model. CO2 emissions were reduced to 129 g/km (predecessor: 139 g/km), thereby fulfilling the Euro 5 norm. However, the 1.6 litre engine can also run on biogas or a mixture of natural gas and biogas. In the case of 100% biogas propulsion, the carbon foot print is almost zero.

The extended CNG range of the seven-seat vehicle represents an improvement of around 25% on its predecessor. These enhancements have been mainly achieved with a new light weight gas tank system providing an increased CNG capacity of now 25 kg (predecessor: 21 kg) and an optimisation of the drivetrain.

Prices for the Zafira Tourer CNG version, which can already be ordered, start at EUR 27,950 (recommended retail price in Germany, including VAT). CNG vehicles like the new Zafira Tourer offer significantly lower running costs than their gasoline counterparts. For example, in Germany CNG is 50% cheaper than gasoline.

Opel engineers increased the volume of the gas tanks to 25 kilograms from previously 21 kilograms. This has helped to boost the operative range in the CNG mode by around 25% to 530 km. Rather than using conventional steel gas cylinders, the engineers opted for state-of-the art composite material including carbon fiber. The use of this lightweight material resulted in a weight saving of 85 kilograms.

Another important innovation that has further increased the range is the use of electronic pressure regulators rather than mechanical ones, as it was the case in the Zafira CNG predecessor model. The electronic regulators ensure that when the gas cylinders are almost empty, even small remaining reserves can be efficiently exploited. In the seven seat configuration, the Zafira Tourer CNG has a clear advantage over its competitors in terms of operating range.

Opel was the first manufacturer to optimise engines for the use of natural gas by employing the clever monovalentPlus system. Under the tried and tested concept the engine has been optimised to use CNG but the vehicle also holds a 14 liter auxiliary gasoline tank. When the CNG tanks are empty, the vehicle automatically starts utilising the gasoline reserves.

On the engine side, the optimisation includes several measures: as natural gas has an anti-knock resistance of up to 130 octane, compression can be increased, yielding greater efficiency. The increase in the compression ratio is also supported by a piston specially designed for use with natural gas. The cylinder-selective sequential injection, with an injection block and four injectors for natural gas and gasoline, also permits precision control of the injection timing and quantity. This reduces harmful emissions, leading in turn to especially clean exhaust gases.