A method includes mixing air and converted fuel from an on-board fuel converter in a fuel mixer to form an air-converted fuel mixture, the air-converted fuel mixture includes a short chain hydrocarbon; mixing the air-converted fuel mixture with a high specific heat diluent to form an air-diluent-converted fuel mixture; mixing the air-diluent-converted fuel mixture with a first amount of fuel to form a homogenous mixture. A system and article are included.