Fuel-consumption and emissions lowering features on the new Sharan. Click to enlarge.

Volkswagen will introduce its new third-generation Sharan MPV (minivan) this summer. The new Sharan, which is larger than its predecessor, will offer a choice of two direct injection TSI gasoline and two TDI diesel engines that are up to 21% more fuel-efficient than the comparable engines of the outgoing model.

Featuring a start-stop system and battery regeneration, the Sharan equipped with the 140 PS TDI—the most popular engine version in Europe for the existing Sharan—will consume 5.5L/100km (43 mpg US), equivalent to 143 g/km CO2.

The two TSIs output 110 kW / 150 PS (148 hp) and 147 kW / 200 PS (197 hp), while the TDIs develop 103 kW / 140 PS (138 hp) and 125 kW / 170 PS (168 hp). Each of these Euro-5 engines is also available with a 6-speed dual clutch gearbox (DSG); it is standard equipment on the 200 PS TSI. For engines ranging up to 170 PS in power, a BlueMotion Technology pack is implemented with a start-stop system and battery regeneration (recovery of kinetic energy by storing it in the battery).

Start-Stop system. As soon as the driver brakes to a stop, shifts into neutral and takes his or her foot off the clutch (with DSG it is sufficient to take the foot off the brake pedal), the engine shuts off momentarily. In the multifunction display the text “Start Stop” appears. Depressing the clutch (or with DSG simply releasing the brake),re-starts the engine and clears the “Start Stop” text. The system saves up to 0.2 liters per 100 kilometers in the city.

Unlike vehicles without the Start-Stop system, the BlueMotion Technology models have an extra battery data module (for acquiring momentary battery charge status); a reinforced engine starter; a DC/DC converter; and a durable deep-cycle glass mat battery on board.

Battery regeneration. During coasting and braking phases of the Sharan—i.e. whenever the driver releases the accelerator pedal or brakes—the system elevates the voltage of the alternator (generator), and this electricity is used to intensively charge the vehicle’s battery.

With this alternator control as a function of engine load, and the optimally charged battery that results, the voltage of the alternator can be reduced whenever this is desirable—e.g. when accelerating or while constantly maintaining a desired speed. The alternator may even be shut off entirely.

This relieves engine load, which in turn reduces fuel consumption. The constantly fully charged battery supplies the vehicle’s electrical system during the stopped phase of the engine (e.g. at traffic lights). Battery regeneration requires special software for energy management and modified engine controller software.

TDI Engines. The TDI with 103 kW / 140 PS is the entry level diesel. The 1,968 cm3 16-valve four-cylinder engine has a power output of 103 kW / 140 PS at 4,200 rpm. At a low 1,750 rpm, the TDI (with a 16.5:1 compression ratio) develops a maximum torque of 320 N·m (236 lb-ft). This turbocharged engine with manual gearbox accelerates the Sharan to 100 km/h in 10.9 seconds, and has a top speed of 194 km/h (121 mph).

The 125 kW / 170 PS TDI of the new Sharan is a 2.0-liter 16-valve, four-cylinder engine also applied in the current Golf GTD. The top speed of the TDI occurs at 4,200 rpm. Between 1,750 and 2,500 rpm, the engine develops a maximum torque of 350 N·m (258 lb-ft). Accelerate to 100 km/h takes 9.71 seconds, and top speed is 207 km/h (129 mph). Combined fuel consumption is 5.71 L/100 km (41 mpg US) with associated CO2 of 151 g/km.

SCR catalytic converter. Both TDIs are fitted with an SCR (Selective Catalytic Reduction) exhaust aftertreatment system. The SCR catalytic converter works together with the additive AdBlue to selectively convert nitrogen oxides (NOx) in the exhaust gas stream to nitrogen and water. An oxidation catalytic converter and diesel particulate filter are also fitted to reduce a wider spectrum of emissions.

The AdBlue, stored in a 17-liter (4.5 gallon) auxiliary tank is continuously sprayed into the exhaust gas via a module downstream of the diesel particulate filter and oxidation catalytic converter. This substance is continuously sprayed into the exhaust gases upstream of the SCR catalytic converter. The metered rate is based on the mass flow of the exhaust gas. Engine management, which receives information from a NOx sensor downstream of the catalytic converter, enables precise control.

Finely atomized by a screen, the urea is converted to ammonia in the hot exhaust gas upstream of the SCR catalytic converter. In the SCR catalytic converter, the ammonia then breaks down the nitrogen oxides into nitrogen and water. AdBlue is consumed at an average rate of about 0.1 liters per 100 kilometers. The tank capacity of 17 liters yields a range of about 15,000 kilometers between fillings.

TSI engines. The Sharan is one of the first MPVs to be offered exclusively with charged and direct injection engines, including gasoline engines. A 1.4-liter TSI engine with a power of 110 kW / 150 PS (at 5,800 rpm) is the new base gasoline engine of the Sharan. Its twincharger—combining turbocharging with supercharging—delivers fuel consumption of 7.2 L/100 km (33 mpg US) gasoline with 95 ROZ; 167 g/km CO2; and maximum torque of 240 N·m (177 lb-ft) between 1,750 and 4,000 rpm. The Sharan reaches a speed of 100 km/h in 10.7 seconds with this engine and a manual gearbox; its top speed is 197 km/h (122 mph).

The supercharger, mechanically driven by a belt, increases the TSI’s torque at low engine speeds. This is a charging unit based on the Roots Principle. A special aspect of this supercharger is its internal gearing, which enables high supercharger performance even at low engine speeds.

At higher engine speeds, the exhaust gas-driven turbocharger (with wastegate control) kicks in. Then the supercharger and turbocharger work in series. The supercharger is operated via a solenoid clutch that is integrated in a module within the water pump. A control gate ensures that the flow of fresh air required for the operating point reaches the turbocharger or supercharger. In pure turbocharger mode the control gate is open. Then the air takes the familiar path of conventional turbocharged engines via the front intercooler and throttle valve and into the induction pipe. Starting at an engine speed of 3,500 rpm the supercharger turns all of the work over to the turbocharger.

At the highest power level, the Sharan is driven by a 147 kW / 200 PS (between 5,100 and 6,000 rpm) TSI unit. The same 2.0-liter engine in turbocharged form is applied in the current Golf GTI, although on that car it has an extra 10 PS. Fuel consumption for the 200 PS TSI in the Sharan is 8.1 L/100km (29 mpg US).

Maximum torque of 280 N·m (207 lb-ft) is available between 1,700 and 5,000 rpm). The 2.0L TSI Sharan accelerates to 100 km/h in 8.3 seconds, and has a top speed of 218 km/h (129 mph).

Other fuel economy features. The 2010 model year Sharan is a completely redesigned vehicle. Among the features contributing to the lower fuel economy are a lighter weight (for example, the Sharan 1.4 TSI BlueMotion Technology was made 30 kilograms lighter than the comparable version of the previous model) and improved aerodynamics, with a Cw of 0.299—a 5% improvement over the previous model.

The new Sharan will launch in Germany at the end of August 2010. Total production for the Sharan (all generations since the initial launch in 1995) is 607,700 units.