Taken from the link
Direct petrol injection with charging
Direct petrol injection is combined with a turbocharger or charge compression with a turbo and a supercharger working in tandem. This enhances the engine's combustion efficiency so the TSI engine power output is much higher than that of conventional, naturally aspirated engines.
Torque when you want it
On the TSI T1.4 160PS the engine-driven supercharger operates at lower revs, with the turbocharger - powered by the exhaust gases - joining in as engine speed rises. The supercharger is powered via a belt drive directly from the crankshaft. This provides maximum pulling power on demand, even at very low engine speeds. TSI engines are designed to deliver maximum torque from engine speeds as low as 1500 or 1750 rpm. And that has the twin benefit of not only increasing your driving pleasure but also cutting fuel consumption.
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The original 1.4 TSI engines in the Mk5 were twin charged in 140 and 170 flavours. Now I belive it is only the 160PS version that has the supercharger as well.
