Imperatives and incentives for meeting the Euro VI exhaust emissions standard

Special importance is given to the environmental footprint of regular-service buses, because these vehicles are very often used in areas that are particularly sensitive to environmental damage. For city centres, suburbs and the fast-growing urban areas in Europe and far beyond, environmental protection is a top priority alongside economic considerations when it comes to the purchase and operation of regular-service buses.

The Mercedes-Benz Citaro opens up a whole new chapter in this area by successfully meeting both environmental and economic objectives, as the first regular-service bus delivered to customers with a Euro VI-compliant engine. This has been achieved with an entirely new engine generation from Mercedes-Benz.

This was the ideal time for Mercedes-Benz again to take the lead in the engine development stakes, with several calls for tenders for procurement contracts stipulating Euro VI as mandatory. Incentive schemes are also now in place for meeting the new exhaust emissions standard.

Development of two completely new engine families

“BlueEfficiency power” was the motto for the development of these completely new engine model series for the Mercedes-Benz Citaro. The family comprises the in-line six-cylinder OM 936 with a displacement of 7.7 litres and the OM 470 with a displacement of 10.7 litres. Other shared features include excellent fuel, AdBlue and engine oil economy and long maintenance intervals for the diesel particulate filter – 120,000 km or two years in the case of the Citaro.

Impressive acceleration and smooth-running characteristics

The new engines impress immediately with their acceleration and power, combined with impeccably smooth running. The acoustics of the weight-bearing structures of the Citaro have also been very carefully designed, including a rigid framework structure for maximum vibration isolation.

High torque already at very low engine speed generates high but economical output at revolutions scarcely above idling speed. This makes for excellent acceleration performance from the bus stop or traffic lights. It also enables the gear change points in the automatic transmission available in the vehicle to be set relatively low, in the interests of fuel economy.