Experimental investigation was carried out to study the burning characteristics, engine performance and emission parameters of a single-cylinder Compression Ignition (CI) engine using nanofuels which were formulated by sonicating nanoparticles of aluminum (A 1 ), iron (F 1 ) and boron (B 1 ) in base diesel. These fuels showed reduced ignition delay, longer flame sustenance and agglomerate ignition. Study of engine performance at higher loads revealed drop in peak cylinder pressures and reduction of 7% in specific fuel consumption for A 1 as compared to diesel. Improved combustion rates raised exhaust gas temperatures by 8%, 7% and 5% leading to increased brake thermal efficiencies by 9%, 4%, and 2% for A 1 , F 1 , and B 1 respectively, as compared to diesel at maximum loading conditions. Volumetric reduction of 25–40% in CO emission, 8% and 4% in hydrocarbon emission was measured when the engine was fueled with A 1 and F 1 respectively as compared to emissions from diesel. However, elevated temperatures resulted into marginal rise in NO x emission.