Disclosed is an internal combustion engine system (100) with heat recovery comprising an internal combustion engine (12) with a waste heat passage (16), an electric motor (28), a heat recovery assembly (1) comprising a working fluid circulation circuit with a working fluid, a first heat source (4; 6) which is adapted to be heated by the waste heat passage (16) and adapted to heat the working fluid, and an expander engine (8), which is operated by the heated working fluid, and a splitting device (24), which is connected to the electric motor (28) and is adapted to be connected to a drivetrain of a vehicle and which splitting device (24) is further connected to the expander engine (8), so that the expander engine (8) is enabled to drive the drivetrain and/or the electric motor (28).The internal combustion engine system (100) further comprises at least a second heat source (32) for providing heat to the heat recovery assembly (1). Disclosed is also a vehicle comprising such an internal combustion engine system (100).