Graphene and carbon nanotubes have drawn interest across many disciplines due to their remarkable properties. We investigated the effects of graphite oxide (GO), single-walled carbon nanotubes (SWCNTs), and cerium oxide (CeO2) nanoparticles on the combustion, performance, and emission characteristics of a four-stroke single cylinder light-duty diesel engine under various engine loads. Shortened ignition-delay (ID) by up to 10.3%, advanced combustion phasing (up to 18.5%), shortened combustion duration (up to 14.6%), improved brake specific fuel consumption (BSFC) by up to 15.2%, reduced CO emission (up to 23.4%), and lowered UHCs emissions (up to 24.1%) were achieved with the addition of SWCNTs nanoparticle at 25 ppm dosing ratio. SWCNTs and GO additives could be effective approach for lowering emissions in diesel engine applications. (C) 2018 Elsevier Ltd. All rights reserved.