New entry-level engine for TT
The turbocharged 158bhp engine can power the Coupe to 62mph in 7.2 seconds - 0.6sec slower than the 2.0-litre TFSI - and on to a top speed of 140mph.
The smaller 1.8 is more efficient than the 2.0-litre, averaging 42.1mpg in the Coupe, compared with 36.7mpg from the bigger engine.
CO2 emissions are 158g/km for the Coupe and 161g/km for the Roadster. This will put both cars into the new band G for road tax when it comes into force here next year.
Left-hand-drive versions will head to European showrooms later this year with a price tag of around £23,300 (29,400 Euros) - £1500 less than the cost of a 2.0-litre TFSI here.