BMW i8 came in with drivetrain issues. After a careful diagnosis we found one of the main problems for the loss of power and rough running. Threw in new plugs, injectors pressure cleaned with flow rate testing, new air box filter, chemical cleaned all other concerning accessories. Further investigation revealed the root cause for the issue. At some point car got bad quality fuel and lot of dirt had got collected in the fuel tank which resulted in inconsistent fuel supply from low pressure pump.