The all-new 2018 Volkswagen Tiguan is coming to market in summer 2017 with a new turbocharged engine the company calls “right-sized.”
The new 2.0-litre turbocharged 4-cylinder is the most advanced ever of Volkswagen venerable engine that has graced just about every model in the company’s line-up. The updated version of the benchmark EA888 turbo direct-injected 4-cylinder (first introduced on the CC of 2009) uses an innovative modification to the conventional four-stroke cycle to offer enhanced power, efficiency and responsiveness.
Though not yet rated by the US Environmental Protection Agency (EPA), it is expected to show improved fuel economy, while returning a 20% improvement in torque (now up to 221 lb-ft), thanks to a modified Miller cycle.
The Miller cycle closes the intake valves shortly before the intake stroke in complete. In this application, the valves are closed sooner, which means longer effective combustion and faster air flow for the incoming gases to alter the air/fuel mixture. It’s apparently called the Budack cycle, with its most important feature being the variable valve timing, which is able to switch between short and long overlaps in valve opening (shorter when the engine is under partial engine load or when idling; longer under full load, such as flat out acceleration).
The results are 184 peak horsepower between 4,000 rpm and 6,000 rpm, and peak torque of 221 lb-ft between 1,600 and 3,940 rpm. The increases are achieved through longer piston stroke and increased compression ratio of the new 2.0 displacement from the previous 1.8-litre engine. Also, a new engine management system with four core processors monitors the system and adjusts as needed.
Other engine improvements include lower friction and a smaller crankshaft main bearing diameter of 48 mm (down from 52) and a narrower balance shaft chain. The engine will be the only powerplant in the 2018 Tiguan, and will be offered in other models.