Volkswagen of America has a nice surprise for potential customers of the new VW Tiguan (2018 model year). The latest iteration of the Tiguan – set to arrive in the United States this summer -- will be the first VW model to be fitted with the new advanced version of the German carmaker’s EA888 four-cylinder gasoline engine.
This new engine is a revised yet improved version of VW’s third-generation (Generation 3) EA888 that boasts of a displacement of 1.8 liters. The 1.8-liter four-cylinder, turbocharged and direct-injection EA888 Gen 3 engine (1.8 TSI) is still what powers current models of the VW Beetle, Golf, Jetta and Passat. VW has made certain updates to its four-stroke cycle to improve not only its levels of power and efficiency, but also its responsiveness, resulting to the creation of the 2.0-liter EA888 Gen 3B engine (2.0 TSI).
Updates implemented on the EA888 Gen 3 engine include using a longer piston stroke, a tweak which was responsible for the increase in the updated mill’s displacement. The piston stroke on the 1.8 TSI is 84.1 mm while on the 2.0 TSI, it is 92.8 mm. VW also modified the engine’s piston crown and combustion chamber, resulting to a higher compression ratio of 11.7:1.
In addition, VW employed new TSI injectors that are designed to inject fuel into the engine’s cylinder at a higher max pressure (3,626 psi or 250 bar). Likewise, up to three injection sequences per stroke could be achieved depending on conditions. Furthermore, VW updated majority of the third-generation like its cast-iron block, aluminum alloy pistons, cylinder head and valve springs.
Additionally, VW introduced a modified Miller combustion cycle – exclusive to the Volkswagen Group – as a result of the quest to make the engine more efficient in the most employed range of driving. Conventionally, the Miller combustion cycle closes the intake valves before the intake stroke ends. However, the so-called Budack-cycle closes the intake valves at an earlier time, resulting to longer effective combustion and faster airflow for the incoming gases. Since this improves the blending of fuel and air, the updated engine consumes less fuel while delivering more torque.
Likewise, the updated engine features variable valve timing system on the intake camshaft. This gives the engine the ability to switch between short and long valve opening, depending on the load.
All these updates have allowed the new 2.0-liter EA888 Gen 3B engine in the 2018 Tiguan to deliver 184 hp of max output at 4,400 rpm and 221 lb.-ft. of peak torque available between 1,600 rpm and 3,940 rpm. The US Environmental Protection Agency has yet to provide the final fuel economy estimates for the updated engine, although VW claims it is more efficient than its predecessor. For now, only the Tiguan features this engine, although this updated mill will soon find its way in VW’s newer models.