The 2.0 TDI Clean Diesel engine in the Jetta develops its maximum power over a low speed range of 3500 to 4000 rpm. The maximum torque of 236 lb-ft (230 N·m) is available from 1750 rpm up to 3000 rpm.

The TDI Clean Diesel engine in the Jetta is the first engine to be introduced to theUS which utilizes the new modular diesel system (MDB) from Volkswagen. Many components of the MDB engines are used in a modular way, such as the exhaust system components and the injection system, turbocharging systems, and forced induction cooling within the intake manifold module.

Besides helping to reduce emissions, Volkswagen also designed the new TDI engine for minimal internal friction, for instance using piston rings with lower pretension and very low-friction camshaft bearings. Energy efficiency has also been optimized by using an oil pump with volumetric control and two pressure levels. An innovative thermal management system makes use of separate coolant loops for the cylinder head and the crankcase during the warm-up phase and has a water pump that can be deactivated.

A complex exhaust gas recirculation system is also used. To conform to the current BIN5-ULEV2 emissions standard in the US, as well as the future LEV3/TIER3 standard, the Jetta is equipped with an emissions control system, including Selective Catalytic Reduction (SCR) system (a diesel particulate filter with SCR coating) that is located near the engine.

The DPF features optimized porosity with high washcoat amounts of a thermally stable SCR coating. The system has low exhaust back pressure and high filtration efficiency.

Timing on US emission regulations. Source: Volkswagen of America. Click to enlarge.

The close-coupled layout enables extremely fast response by the oxidation catalytic converter and the SCR catalytic converter. The SCR catalytic converter significantly reduces oxides of nitrogen (NO_x) using the additive AdBlue additive. Compared to the NO_x storage catalytic converter (NSC) of the previous model, the use of the SCR catalytic converter not only further reduces emissions, but also improves fuel economy.

Close-coupled exhaust gas aftertreatment in the EA288 diesel. Source: Volkswagen of America. Click to enlarge.

Optimized aerodynamics. Volkswagen has introduced numerous innovative aerodynamic modifications into the design and equipment of the Jetta. In the front of the car, air drag has been reduced by the new bumper, optimized air intakes, and aerodynamically refined rain gutters on the sides near the A-pillars. A closer look reveals underbody panels at the rear axle and sill covers with wheel spoilers.

Jetta models equipped with the 1.8T engine also have modified brake ventilation channels. Jetta GLI and Jetta Hybrid models sport special aerodynamic elements such as new front/rear spoilers and sill extensions.

One new aerodynamic feature on the Jetta TDI 1.8T and 2.0 TDI Clean Diesel is a closeable shutter for the radiator grille. Closing the radiator shutter helps shorten the warm-up phase of the engine due to reduced air cooling. If the engine coolant temperature drops below a predefined temperature threshold while driving, the radiator shutter remains shut. Once the engine moves beyond the warm-up phase, the shutter can open and close based on vehicle speed and cooling demands. When closed, frontal airflow is guided around the body, which helps to improve the car's aerodynamics and thus reduces fuel consumption.

New driver assistance systems. Available technologies include Blind Spot Detection plus rear cross-traffic alert and frontal collision warning, as well as Bi-Xenon headlights with Adaptive Front-lighting System (AFS), turn signal, and LED Daytime Running Lights.

• Blind Spot Detection. Blind Spot Detection utilizes a flashing symbol in the outer area of the side mirrors to make the driver aware of vehicles in the blind spot next to the Jetta or approaching from the rear. This is intended to help improve driver awareness when changing lanes. The system uses radar sensors to “monitor” a space around the vehicle with a range of approximately 65 feet. Customers who choose the Blind Spot Detection option automatically get the rear cross-traffic alert assistance system as well.

• Rear cross-traffic alert. The new rear cross-traffic alert assistance system is offered in tandem with Blind Spot Detection. The system not only helps alert the driver to stationary and moving vehicles directly behind the vehicle; it also detects vehicles approaching from the side which may be difficult for the driver to see. The radar-based sensor module can even detect objects up to 65 feet away. In case of an impending collision, the system gives an acoustic warning.

• Frontal collision warning. The frontal collision warning system uses radar sensors to continually monitor the distance to traffic ahead of the vehicle. Within physical system limits, frontal collision warning warns the driver of critical front-end collision situations, both acoustically and visually by a clear warning symbol in the instrument cluster. The radar sensor acquires both the position of stationary cars and motorcycles and those moving in the same direction as the vehicle. The sensor is hidden behind the VW logo on the radiator grille.

Bi-Xenon headlights with LED daytime running lights are now available. Also integrated in the new generation of headlights is what is referred to as the Advanced Front-lighting System (AFS). In this system, the headlights track the steering angle and can be turned up to 15 degrees, illuminating corners in turns.

The 2015 Volkswagen Jetta is expected to arrive at US Volkswagen dealers in the third quarter of 2014.