Speed wobbles worry experts

The only black cloud which has hung over the Audi TT since its 1998 launch in Europe has been the quattro model's uncertain high-speed stability.

The TT quattro's handling polarised opinion from the start. Many European motoring journalists praised the car's eagerness to slide sideways, or oversteer - an unusual characteristic for a four-wheel-drive car.

But leading German magazine Auto Motor and Sport expressed concerns about the car early in 1999, after testing it against the Audi A3 and S3 quattros, and the Volkswagen Golf V5 4Motion. All use the same Haldex drive system.

The magazine reported that the TT became unsettled at very high speeds and snapped into oversteer with little warning. The other models did not exhibit the same behaviour.

Then came a spate of high-speed crashes on Germany's autobahns. Experts attributed the problem to aerodynamics - at 200km/h, the TT generated about 60 per cent more lift at the rear than a Golf.

Audi has maintained that the chassis set-up of the TT quattro is in line with its high-performance rivals, but has moved to make it more user-friendly.

All cars built since December 1999 have had mildly modified suspension, thicker anti-roll bars, switchable Electronic Stability Program (ESP) and a small rear spoiler to reduce high-speed lift.

About 60 TTs were sold in New Zealand before the changes. Local importer European Motor Distributors has offered to retro-fit the larger anti-roll bar and spoiler for its customers, but not the revised suspension or ESP, which must be added at the factory.

However, EMD says only a handful of customers have thought it necessary to modify their vehicles, since the stability problem occurs only at highly illegal speeds in this country.