eTSI with 110 kW. Not every driver is able to charge their vehicle at home or work. In these cases, Volkswagen still makes it possible to use electrical energy with the Passat eTSI. Here, electrical power is generated through the conversion of kinetic energy – the braking or recuperation power of a vehicle. This is made possible by the mild hybrid drive, which is new to the Passat. As in the new plug-in hybrid models (eHybrid), the 1.5 TSI evo2 also forms the technical heart of the powertrain. The eTSI is coupled to a 48 V lithium-ion battery and a 48 V belt starter generator that provides an output of 14 kW and a torque of 56 Nm. The 48-volt system acts like a type of electric booster and thus offers excellent performance when moving off. At the same time, the technology makes it possible for the 1.5 TSI evo2 to be completely switched off, thereby enabling coasting and temporary electric driving. The result? Up to 0.5 l/100 km less fuel consumption.
The technical details of the eTSI. In addition to technical features such as the TSI evo combustion process and VTG turbocharger, the 1.5 TSI evo2 with a torque of 250 Nm as an eTSI is additionally equipped with Active Cylinder Management (ACTplus) compared to the version used in the eHybrid models. With ACTplus, two of the engine’s four cylinders are switched off as often as possible, depending on the operating situation. The second and third cylinders are designed to be taken out of the fuel supply at low and medium loads and speeds. Efficiency thus increases in the active cylinders, while the passive cylinders run almost loss-free. When the throttle is opened, they immediately become active again. Compared with the first 1.5 TSI evo generation, this switching on and off of the cylinders has been improved once more to guarantee smooth engine running.
Operating principle of the eTSI. 48 V technology permits transmission of higher electric power levels with smaller conductor cross-sections and a compact battery – thus also resulting in low additional weight. Compared with vehicles with pure 12 V technology, this leads to recuperation of a significantly larger amount of energy during braking or deceleration. The energy stored in the 48 V lithium-ion battery is used to drive a 48 V belt starter generator and to supply the 12 V on-board electrical system via a DC/DC converter. The water-cooled belt starter generator has the role of alternator and starter. At the same time, it acts as a compact electric motor, which increases the drive torque without any delay when moving off. The output of the generator is transferred by the belt drive. The generator also restarts the combustion engine – which is switched off as much as possible while the vehicle is moving. The bottom line is that the 48 V mild hybrid drive combines low consumption and emission values with excellent moving-off performance in daily operation.