The OM656 is based on a modular design that is shared with other
4-cylinder and
6-cylinder,
petrol and diesel engines. It is the replacement to the previous
V6, in order to maintain the cost of production between different engines. The OM656 has
dual overhead camshafts with
variable valve timing, and uses
AdBlue injection and
exhaust gas recirculation to reduce emissions. The cylinder walls are coated with
arc sprayed steel whose increased porosity aids oil film strength to reduce friction. == Models ==