Audi decided against using the 'S' label on the A1 because it doesn't come with the Quattro all-wheel drive system.
According to PistonHeads.com, Audi considered using the S1 name for the range-topping A1 1.4 TFSI, which it will be premiering at the Paris motor show next week, but later chose not to put an 'S' label on the car.
Apparently, Audi didn't want to dilute the 'S' badge's cache by applying it to a car without its famed quattro all-wheel drive system.
The Audi A1 1.4 TFSI is a front-wheel drive compact hatch fitted with VW Group's award winning 1.4 liter TFSI engine. For the A1's top variant, the engine is dialed up to 136 kW (185 PS / 182 hp) and 250 Nm (184 lb-ft) of torque. The A1 1.4 TFSI is also fitted with Audi's seven-speed S tronic dual-clutch transmission. The 0-100 km/h sprint for this A1 takes just 6.9 seconds and the car has a top speed of 227 km/h (141 mph). Fuel-economy is 5.9 liters/100km (40 US mpg) and CO2 emissions are 139 g/km (224 g/mile).
The model will make its public debut at the Paris motor show on October 2 (September 30 for the press) and will go on sale later in the year.