Volkswagen may be in deep kimchi over the entire Dieselgate scandal, but when the latest generation of the EA211 TSI evo motor was unveiled at the 37th International Vienna Motor Symposium recently, all eyes were on a different kind of fuel option. Which is good, because VW is hoping to get diesel out of the public conscience as soon as possible.
According to the German automaker, the engine you see here is the first of many future power plants. The turbocharger on this little four-banger features variable turbine geometry, a first for volume-produced spark ignition engines, and once coupled with VW’s latest integrated exhaust manifold technology, it will likely spell big things for the automaker. The 1.5-liter TSI will become available in late 2016 with outputs ranging up to 148 horsepower.
These tiny turbo engines are far more efficient and potent than anything we’ve seen to date from the automaker, and while the graph proves that torque piles up around the 1,300 mark, the real gains are felt mid-range, with efficiency being the ultimate endgame.
A decade has passed since Volkswagen first began offering direct-injection, turbocharged spark-ignition engines with TSI technology, and as single-stage turbocharging morphed into two-stage setups, things got complicated quickly. From the moment integrated charge-air cooling and the use of engine-encapsulated exhaust manifolds came into play, the thermodynamic perks of these cylinder deactivating turbo motors brought power and efficiency to the forefront.
Compared to the previous 1.4-liter TSI engine, fuel gains are now up 10% across the board, and VW is quick to stress that the improvements in fuel economy “take effect across a wide range of the engine map.”
Simply put, VW has found a way to utilize “atmospheric plasma spray” to create tiny lubrication pockets in the engine block’s cylinder walls. This encourages a smoother sliding piston ring, and means better heat dissipation, less risk of inferior fuel combustion, and a better promise of a hybrid/turbo technological advancements. Got it? OK. Let’s get nerdy.
While the engine’s cylinder head has been re-engineered for improved heat dissipation and other features, VW took an adjustable intake cam that utilizes a high-speed hydraulic actuator to allow varying degrees of cylinder-fill control.
Cylinder deactivation has been improved as well, and by forcing the engine to rapidly warm up, Volkswagen has both improved cabin heating times and engine friction reduction during the crucial warm-up process. Switching over to a low-viscosity 0W20 oil helps out as well, and when compared to the outgoing 1.4-liter TSI engine, the variable turbo’s torque curve kicks in 35% faster.
The indirect charge-air cooling system has been bumped up in both sizing and mounting locales as well while staying compact in size, which helps make the charge hitting the turbine that much cooler. This results in more power and better fuel efficiency. A more precise atomization of fuel in the injector spray pattern helps on both fronts as well.
When all of this is pieced together, you get a small, lightweight, torque-rich, and fuel efficient power plant with a variety of applications throughout VW’s lineup. Expect to see the new EA211 in the new Golf, Sportwagen, Jetta, and potentially the Beetle here in the U.S.