This research explores possibility of using a new mixture of diesohol, diesel/butanol instead of diesel/ethanol, in commonrail compression-ignition engine, as an attempt to solve the miscibility problem in diesel/ethanol and the water absorption in ethanol. Butanol and diesel were blended at butanol concentrations of 5, 10, 15, 20, 25 and 30 by volume without any emulsifier. The butanoldiesel blends were then tested with Isuzu engine (model 4JJ1) without any modification for engine performance, fuel consumption and emissions, with comparison to commercially available diesel in the market. The results reveal that butanol/diesel blends up to 15 – 20% (without emulsifier additive) can be used in commonrail engine without any modification to the engine since ECM (electronic control module) of the engine can maintain set lambda value despite the butanol blending. Higher than 15 – 20% butanol blending in diesel deteriorates engine performance and fuel consumption. Furthermore, oxygen content in butanol helps achieve more complete combustion