SI gasoline engine running a Miller Cycle with a higher compression ratio. Wayne Gerdes – CleanMPG – April 28, 2016 2016 Volkswagen Jetta with the 1.4L TSI mated to a 5-speed provides owners a 28/40 mpgUS city/highway rating. With the all-new 128 hp and 148 lb-ft of torque, direct injected and turbocharged 1.5L TSI evo, next year’s 2017 Jetta could offer a 30/44 mpgUS city/highway rating on gasoline almost matching the unavailable 2.0L TDI! Vienna, Austria -- At the 37th International Vienna Motor Symposium, VW introduced its latest EA211 TSI evo engine. The 1.5L evo is the first model of the brands future generation of spark ignition engines scheduled for launch in late 2016, initially with outputs of 129 hp and 148 hp variants. One of the numerous highlights of the new engine is the turbocharger with variable turbine geometry, which features for the first time in a volume-produced gasoline fueled spark ignition engine. Future emissions legislation demands even lower fuel consumption, CO2 and smog forming emissions. In order to achieve the regulatory hurdles, a large number of innovations have been combined in the new EA211 TSI evo. The result is a maximum torque that is available at just 1,300 rpm and maintains its peak over a broad RPM while reducing consumption by up to 10 percent. Volkswagen is Moving the Efficiency Bar The all-new EA211 TSI evo is up to 10 percent more efficient compared with the current European based 123 hp 1.4L TSI. The improvements in fuel economy occur across a wide range of the engine load map. Details of the new/revised technologies featured are as follows: Miller combustion cycle with a high compression ratio of 12.5:1 Turbocharger with variable turbine geometry (VTG). Common-rail injection system with up to 350 bar pressure Innovative thermal management Cylinder deactivation (ACT) APS-coated cylinder walls (atmospheric plasma spray) The cylinder liners in the 148 hp variant are coated using the APS process (atmospheric plasma spray). Fine-grain spray powders combined with an optimized grinding process lead to the creation of tiny lubrication pockets that ensure the piston rings glide smoothly with low friction and little wear. It also provides increased heat dissipation compared with a straight cast iron sleeve resulting in improved antiknock properties during combustion and improved corrosion resistance with low quality fuels on global markets. APS technology achieves particularly good wear resistance in hybrid applications, whereby the cold engine is often started under higher loads. The cylinder head has been extensively re-engineered. Initiatives include optimization of the water jacket for improved heat dissipation and adaptation of the valve angle and combustion chamber for the best possible execution of the Miller combustion process. The proven concept of the exhaust manifold integrated into the cylinder head has been retained. In contrast to the EA211, the intake camshaft is adjusted using a high-speed hydraulic camshaft actuator with a central control valve. The adjustment speed of up to 300° of crank angle (CA) per second enhances the dynamics of the cylinder-fill control. 4 to 2 cylinder deactivation, another subassembly from the European EA211 engine, has been improved and is entering volume production with the TSI evo. This improves engine efficiency by closing off the intake and exhaust valves of cylinders two and three up to a mid-load range, while at the same time deactivating fuel injection. The new map-controlled cooling module provides the engine with efficient thermal management. The cooling module ensures the water in the crankcase and the engine as a whole remains stationary during the warm-up phase. The resulting rapid engine warmup improves heating in the car's interior and reduces engine friction during the warm-up process. A further benefit of the map-controlled cooling module is that the engine can be cooled in close correlation with its requirements across the entire operating range. Other features of the TSI evo include an extensive friction reduction package. This encompasses a map-controlled, fully variable oil pump, polymer coating of the first main crankshaft bearing and is now built for 0W-20 oil. The Miller combustion cycle is key to performance and efficiency of the all-new EA211 TSI evo. The improvement in thermodynamic efficiency has been systematically implemented through four main development targets: Increase in the geometric compression ratio to improve efficiency at lower RPMs Reduction of the final compression temperature through early intake valve closing and resulting expansion cooling during the intake stroke Optimization of the charge motion enhancing flame propagation to reduce knock tendencies at high specific loads Increase in charge density through efficient exhaust gas turbocharging A world first for the TSI evo is the use of an exhaust gas turbocharger with electrically actuated variable turbine geometry (VTG). Due to early intake valve closing in the Miller combustion cycle, volumetric efficiency is lower than for an engine with standard valve timing. Under partial load, the resulting de-throttling leads to a fuel-consumption benefit for the TSI evo. High charge pressure balances out the lower effective stroke volume to create high low-end torque. At low engine speeds, this places very high demands on the turbocharging system. Through adaptation of turbine flow characteristics to match the operating points, an exhaust-gas turbocharger with variable turbine geometry presents the opportunity to provide very high turbine output and high charge pressure from low RPM. The increased accumulation effect on the VTG turbine in combination with a reduced moment of inertia in the turbocharger results in improved instantaneous response. Compared with the 123 hp 1.4L TSI, the step change in load to the maximum torque takes place 35 percent faster. Overall, VTG technology forms an integral part of the TSI evo combustion process. The indirect charge-air cooling has also been modified. In contrast to the EA211, the cooler is located in the pressure pipe, downstream of the compressor outlet and before the throttle valve, meaning it, too, is cooled. The new installation position made it possible to increase the size and performance of the cooler, while maintaining a very compact overall package. It is now able to reduce the temperature of the intake air to just 28 degrees F above ambient. The injection system is the first application of the fourth-generation Volkswagen direct- injection system. Optimization of the system and its components facilitated an increase in injection pressure to 5,075 psi, mush higher than a typical 2,900 psi system most DI engines use today. The smaller droplet size improves mixture formation, leading to a substantial reduction in particulate emissions. Reducing the diameter of the injector tip to 6 mm is beneficial for integration into the combustion chamber, improves stiffness and reduces temperatures at the injector. With 40+ percent thermodynamic efficient I4s in the 4th gen Toyota Prius, upcoming Hyundai IONIQ and possibly the all-new VW 1.5L TSI evo, the combustion engines progress has not yet to reach its ultimate potential. I hope we will see a Golf or Jetta with one late this year as well.