My car a 1.8t was designed to counter the high company car tax, by providing big engine performance with smaller emissions. It only appears to produce about 3% more co2 than a normally aspirated 1.8 engine. Yet it has about a third more power.

Turbos on the face of it would seem to allow us to reduce engine size and emissions without sacrificing power.

Why are they not being used more widely?
--
Stuart