According to a recent report, the Audi S1 could be coming within the next 18 months, which puts it mid to late 2013.
What Car says the model will likely be based on the A1 Quattro, but feature a detuned 2.0-liter four-cylinder petrol engine and it is rumored to produce about 220 horsepower. This means the model can accelerate from 0-100 km/h in just over 6 seconds and hit a top speed of 240 km/h.
There's also word of an RS1, but a spokesperson said "at the moment the Quattro is the top of the range, but there are no decisions that have been made yet".
