WITH the unveiling of the low, low consumption Corsa Eco, Vauxhall has introduced the most economical production petrol engine car in its class anywhere in the world.

Corsa Eco returns 57.6mpg in the combined fuel consumption mode, and sets dramatic new standards for low emissions, at only 118 g/km, that in turn mean reduced vehicle excise duty.

Vauxhall's diesel-powered Astra Eco4 has a combined fuel-use figure of 64.3mpg.

The Eco option package Corsa - it goes on sale this month - is based on the Club model and including the £500 cost of the Easytronic gearbox will have an on-the-road ticket of £8,445.

Powered by the 1.0-litre Ecotec engine, the Easytronic automated shift gearbox was previously only available in 1.2-litre models. Easytronic combines the flexibility and convenience of an automatic transmission with the sporty character and economy of a conventional manual gearbox.

Vauxhall's engineers have further developed the small car's aerodynamics and power train in particular, basing their work on the Corsa 1.0-litre with manual transmission.

The Corsa 1.0, already an extremely economical car, returns 50.4mpg putting it at the top of its market segment. To cut aerodynamic drag still further, the Corsa Sport's roof spoiler and side skirts were adopted along with large-diameter wheel covers that guide the air flow smoothly past the wheels.

An aerodynamic undertray also improves air flow underneath the Corsa, and the size of the cooling air ducts has been reduced so that less air flows through the engine compartment. The body has been lowered by 10 mm.

For Corsa Eco the gearbox has been programmed so that the engine runs in the speed range that offers the most favourable fuel consumption under normal driving conditions. Full power is available whenever needed by pressing the pedal to the kick-down position.

The Eco engine is a real weight saver, for example, it includes hollow cast camshafts, and a gross weight of only 82.5 kilogrammes. It develops 58PS and, as a three-cylinder unit, has certain fundamental advantages as compared to a four-cylinder design.

For the technically-minded it has only three pistons and with a reduced number of other moving parts, internal friction is lower. Very small roller cam followers are installed in the cylinder head to operate the valves instead of the conventional bucket-type tappets, and here friction is cut by about 70 per cent. Low-viscosity 0W30 engine oil - the same as used in the new Vectra's engine - is specified as a final means of reducing internal friction losses.

The Corsa Eco also features electric power steering, which consumes energy only when the steering wheel is being turned. Depending on the road on which the car is being driven, this can cut fuel consumption by between two and five per cent.

Technical details at a glance

Engine: 1.0 12v Ecotec

Displacement: 973 cc

Number of cylinders/valves: 3/4 per cylinder

Power output: 58 PS; torque 85 Nm at 3800 rpm

Gearbox: Easytronic automated-shift

Ratios (:1): 1st / 2nd / 3rd / 4th / 5th gear - 3.73 / 1.96 / 1.31 / 0.95 / 0.76

Reverse / final drive (:1)3.31 / 3.94.

Performance: 0-60mph in 18.0 secs; top speed 98 mph

Fuel consumption: Urban 43.4 mpg, extra-urban 70.6 mpg, combined 57.6 mpg. CO2 emissions: 118g/km. Exhaust emission category Euro 4.

Updated: 10:40 Friday, May 03, 2002