Auto Bild reports that the next-generation Q3 that will debut in 2018 will grow in length and width by a bit. This is because the Q1 needs more room at the bottom of the range.
The SQ3 model will be equipped with the 240 horsepower 2-liter biTDI diesel engine. The RS Q3 will continue to use a turbocharged 2.5-liter TFSI which should compete well with the rival VW and Mercedes models that use 2-liter engines.
Then there is the Q3 e-tron. The Q3 e-tron will share an engine with the A3 e-tron and may develop 250 horsepower. We still don't know if it wil be based on a 2-liter diesel or the same 1.4 TSI though. And we likely won't know for another 3 or 4 years.