The Mercedes-Benz Viano

The Viano can be ordered with the four-cylinder in-line CDI diesel engines or one of a pair of V6 petrol-driven power units.

The V6 engines

The torquey and flexible V6 power units feature two intake valves and one large exhaust valve (41 mm in diameter), plus a balancer shaft. They have already made a name for themselves in various Mercedes-Benz passenger car model series, displaying smooth running characteristics and adding extra pleasure and verve to the driving experience. The 190 hp variant develops torque of 270 Nm over an engine speed range from 2750 rpm to 4750 rpm, whilst its 218 hp sibling pushes this figure up to 305 Nm between 2800 and 4750 rpm.

The compact crankcase in the V6 engines (with a cylinder angle of 90 degrees) is constructed out of an environment-friendly smelted aluminium alloy in a new process known as High Pressure Die Casting (HPDC) and weighs only 26.7 kg. HPDC is significantly more precise than conventional methods and reduces the number of subsequent processing steps otherwise required. Also new are the cylinder liners, which are made from Silitec – an aluminium-silicon alloy – and reduce exhaust emissions and oil consumption with their homogenous surface structure.

The petrol engines available for the Viano are equipped with the Bosch Motronic ME 2.8 system, which communicates with the control units in the transmission and the ESP dynamic handling system. Dual ignition works in tandem with large valve cross sections to cut fuel consumption, thus improving emissions figures, and also helps push replacement intervals for the long-life spark plugs up to 62,500 miles.

The Viano V6 engine can cope with exhaust gas recirculation rates which lower fuel consumption and deliver improved emissions quality accordingly. The stable combustion also happens to produce an extremely high ignition retard potential, which helps to heat up the catalytic converters quickly in the warm-up phase with the result that their effects are felt sooner. With two catalytic converters close to the engine and two in the underfloor area, the V6 power unit already meets the EU4/I emissions control standards yet to come into force.

An integrated quality assurance concept which begins with engine production – at the Mercedes-Benz engine plant in Bad Cannstatt, Stuttgart – lays the foundations for a low-maintenance and extended service life. For example, automated leak test rigs are integrated into the assembly process. The concept also includes innovative testing processes, which carry out checks on the engine's mechanical system, ignition, injection and full range of sensors in a matter of 60 seconds. When out on the road, an on-board diagnosis system monitors the signals sent out by the sensors and any faults can be noted when the vehicle goes in for a service. Finally, the active service system ASSYST constantly monitors the oil level when the vehicle is in operation and uses the information it collects to calculate how much oil is required and how many miles remain until the next oil change is due. Depending on how the vehicle is used, oil change intervals can stretch to as much as 18,600 km (or once a year).

The CDI engine

The Viano can be ordered with a four-cylinder in-line diesel engine with second-generation CDI technology which has already proved its mettle in the E 220 CDI Saloon and Estate models. The engine output is considerably higher than in the predecessor models, rising from 122 hp to 150 hp.

The driver senses the hike in output at lower engine speeds in particular, thanks to the extra agility of the engine and the added driving pleasure it provides. This new unit develops 330 Nm from 1800 rpm to 2400 rpm.