19 Apr 02
One of the previous problems engineers have had with stratified-charge technology has been high nitrous oxide (NOx) emissions, due to the excess of air. In Audi's FSI engine, this has been controlled by a new exhaust gas recirculation system, and total NOx emissions are cut by up to 70%. Up to 35% of the total exhaust gas is diverted back up into the combustion chamber - effectively sent back to be ignited again. This system works in conjunction with twin catalytic converters, containing NOx sensors, which convert the oxides back into harmless nitrogen gas, as present in the atmosphere naturally.
The 1.6 FSI has received further modifications in line with the engine's increased power. Most importantly, its suspension has been revised, with more progressive springing, which gives a softer ride at low speeds but firms up quickly under pressure and hard cornering, and retuned dampers; this revised set-up will feature on all A2 models for the 2003 model-year. Disc brakes have been fitted at the rear, to increase stopping power, and a larger 42-litre fuel tank has been fitted to give a longer range - over 700 km - between fuel stops (Audi expects FSI buyers to use their cars for more long-distance trips than other A2 buyers, who see their cars predominantly as city runarounds). The final drive ratio, or setting of fifth gear, has also been raised to give more relaxed and economical high-speed cruising. And subtly, the rear spoiler is slightly larger to give increased downforce - really only an issue if you plan to head flat-out down the autobahn - and the front wheel arches are very slightly flared for improved aerodynamics. The FSI is also the first A2 to feature a new single 'spineless' windscreen wiper, stronger, more efficient and more aerodynamic than a traditional hinged wiper, and also to be fitted to all A2 models later this year.
