The main focus of ROTA 2030 program is to identify how to enable further fuel savings giving the efforts implemented by Inovar-Auto, e.g. at crankshaft area.In a way to reduce friction losses and fuel consumption, OEMs are adopting features like variable oil pumps, new crankshaft oil drilling (e.g. one main bearing feeding two connecting rod bearings) and new configuration for the main bearings oil grooves. Usually a full groove (180°) is specified for the upper main bearing once it delivers the necessary oil flow and pressure to the connecting rod bearings with a cost effective manufacturing process. By adopting a partial groove configuration, which can typically vary from 90° to 170°, the overall oil flow to the bearings can be reduced once side flow is reduced. Such design solution enables the oil pump to work more efficiently specially when in a variable flow design. The challenge remains on keeping Minimum Oil Film Thickness (MOFT) safe to ensure robustness and durability. However, the adoption of partial grooves increases manufacturing costs considerably.Using CFD simulation and dynamometer engine test, a new optimized main bearing oil groove was developed, which combines the reduced flow of the partial oil groove with the manufacturability of a full groove.