A decade ago, being able to experience the performance of a sports car was a rare thing. It made certain cars really stand out, like the Golfs of old as they could deliver great economy or power depending on the driver’s mood. With safety requirements getting stricter year after year, manufacturers have had no choice but to beef up their vehicles not just with more steel but safety equipment as well. Consumers are happy to be safer, but the cars now weighed a lot more than they did before. Something had to be done. Fortunately, Volkswagen’s solution brought a new dimension of fuel-efficiency and performance to the cars people drove every day.
That solution comprises of two technologies: the TSI engine and the DSG transmission.
TSI began when the company decided to combine the best of their TDI (turbo diesel, direct injection engines) and FSI (fuel stratified) engines. The ‘TSI’ name is now used on a variety of Volkswagen’s engines, but generally refer to modern, turbocharged engines with comparatively low displacements. The technology in these engines keeps getting upgraded, but the name remains.
In its latest iteration, Volkswagen have incorporated a number of innovative changes. A variable-geometry turbocharger is now used, allowing peak torque to be achieved at just 1300rpm while maintaining a relatively flat torque curve. ‘Cylinder-deactivation’ technology on the other hand, effectively reduces the displacement of the engine when power isn’t needed. So you could be driving a 1.5-litre TSI unit but only burning 3/4 the amount of petrol of a comparable engine.
The cylinders are also coated in APS plasma, which reduces friction – while an innovative heat management system works in the background to minimise energy losses. These tweaks may seem minor, but this generation of engines is up to 10% more efficient than the last.
Just like TSI, DSG refers to a number of few types of gearboxes employed by Volkswagen, usually of the 6- or 7-speed variety. DSG combines the efficiency of a manual with the ease-of-use of a traditional automatic. Typically, these are designed with one clutch for odd-numbered gears, and another clutch for the even-numbered gears.
Having two clutches allows a computer to preselect the next gear before the shift occurs. This means there’s little-to-no power wasted between gear changes as the engine is always sending power to the wheels.
By combining TSI and DSG, you get a powertrain that maximises power and minimises losses from friction, heat and idling. That’s how Volkswagen manages to make affordable vehicles that drive like performance cars while delivering better emissions and fuel-efficiency.
