WOLFSBURG, Germany - All Volkswagen group gasoline-powered cars will be fitted with fuel-saving direct injection by 2005, according to VW Chairman Ferdinand Piech.
The first example will be the Lupo FSI (fuel stratified injection), due on sale later this year. The special Lupo uses a 1.4 liter, four-cylinder engine that develops 105hp.
Running on sulfur-free gasoline (less than 10ppm) the Lupo FSI averages 4.9 liters per 100km in the official European test cycle - 6.3 liters in the city; 4.1 liters in country driving.
The same engine with indirect injection and 101hp uses 9.3 liters in the city and 5.1 liters on the open road.
Stratified injection means that the air-fuel ratio is rich near the spark plug and lean elsewhere in the combustion chamber. The lean mixture is ignited by the explosion of the rich mixture close to the plug. The result is that less gasoline is pumped into the chamber.
The Lupo FSI is built on the same line as the 'three liter' diesel Lupo in Wolfsburg. Many of the special lightweight body structures used on the diesel Lupo - which can travel 100km on three liters of fuel - can be found on the FSI.
The FSI also uses the same transmission - a normal cogwheel unit with automated control and Tiptronic shifting mechanism.
To limit nitrogen oxide (NOx) emissions from the lean burn, VW acquired a patent for a Toyota catalyst. The special catalyst collects NOx while the car is driven in the fuel-saving stratified fuel injection mode.
When the collector is filled, the engine briefly shifts to normal running conditions - 14.7 parts of air to one part of gasoline. It then blows out the NOx residue. The driver does not notice the change.
VW says its catalyst can withstand higher sulfur content than the Toyota catalyst because it adds barium to the mix of platinum, rhodium and other rare metals used in the device.
Barium is not disabled by sulfur, so unlike the Toyota catalyst the VW unit can also be used in countries where sulfur-free gasoline is not available. But there is no fuel saving under such conditions because the engine rarely reaches the stratified mode.
The Lupo FSI will go on sale in Europe in late autumm. It is expected to cost slightly more than the 'three liter' Lupo diesel.
Volkswagen's Golf and Polo ranges are expected to be expanded with 1.4-liter FSI models soon.
VW engineer Bernd Stiebels, one of the creators of the FSI, is confident of its success.
'It is not confined to countries with very low sulfur content in their gasoline and it is an extremely reliable engine,' Stiebels said.
'That the 1.4-liter engine can be converted to direct injection proves that any modern engine can be converted into a gasoline saver.'