A tire pyrolysis oil (TPO) produced from waste tires was tested in a 6-cylinder, compression ignition, turbocharged, 6.9 L heavy-duty engine. The thermodynamic parameters, engine performance and exhaust emissions of the engine fuelled with TPO were benchmarked against results of the engine fuelled with commercial diesel fuel (D2). Experiments were conducted in two operating modes, with and without intercooler, at two different engine speeds and at various loads. Impact of thermodynamic and engine performance parameters on combustion process were systematically analyzed in terms of cause and effect phenomena through mechanisms initiated by the fuel properties. The original contribution of this analysis arises from holistic assessment of combustion phenomena, engine performance and emission characterization of a modern turbocharged CI engine fuelled by the pure TPO. Results indicate that TPO can be efficiently used in turbocharged non-intercooled CI engines at high loads, which opens its use in power generation. (C) 2015 Elsevier Ltd. All rights reserved.