Engine [2015-2016, B5254T12]: Design: Engine
The entire engine is made of aluminum.
The engine has a compact "pent-roof" designed combustion chamber and V-arranged valves. This gives optimal and fast filling and direct flushing via the inlet manifold followed by the combustion chamber (cross-flow) and the exhaust channel.
The squish surfaces together with the centrally positioned spark plug provide optimal combustion of the air/fuel mixture, low knock sensitivity and low, stable exhaust emissions.
The engine's oscillation-mounting consists of an engine bracket bolted in the cylinder head. The engine bracket meets a bracket which is secured in the side member. The other attaching point is located between the transmission and body. A third attaching point for absorbing reaction forces and rotational forces in the bearing bracket for the drive shaft.
The cylinder head is "chill" cast, a slightly slower procedure than die-casting. This is so to integrate exhaust, inlet channel, water and oil casing in the design.
The engine is approved according to emission requirements Euro 5. All bearings are lead-free. Screws are Crome 6+ -free.
The bio-ethanol engine is a flexifuel engine. The engine has a new cylinder head with valve seats on the inlet side and new fuel distribution pipe compared to the gasoline engine. These parts have harder surface coating to maintain service life as bio-ethanol (E85) has a corroding effect.
Valve play is slightly less and the fuel injection supply manifolds have more capacity than on a petrol engine. The bioethanol engine has closer service intervals than a petrol engine
The petrol engine is powered by RON 95 fuel. The bioethanol engine is a flexifuel engine and is powered by bioethanol (E85) or RON 95 fuel and all possible mixtures of these two fuels.
The bioethanol engine has a pre-mounted engine block heater that should be used to facilitate starts at low temperatures, In addition, the amount of gasoline in the fuel mixture should increase at temperatures lower than -10°C, to facilitate cold starts. Because bioethanol has a lower energy content than gasoline the engine uses up 40 % more bioethanol compared with gasoline.