In today's application, it is obligatory to formulate the use of diesel in an environmentally benevolent manner. So, in this experimental study, an attempt was made to increase the performance and reduce the exhaust emission by blending various alcohols such as n-propanol and n-butanol separately at different proportions like 4% and 8% by volume with diesel, also to compare the effect of blending n-propanol and n-butanol separately with diesel, on performance, combustion and emission characteristics. The performance, combustion and emission characteristics observed while using blended fuels were analyzed and compared with that of diesel as fuel without adding alcohols. From the performance analysis, it was reported that, at 80% load, the brake thermal efficiency was increased by 1.579%, 7.635%, 8.917% and 10.518% for the addition of 4% n-propanol, 8% n-propanol, 4% n-butanol and 8% n-butanol with diesel respectively. The emission test concluded that, the smoke density was increased by 12.891%, 5.078%, 11.338% and 14.063% for the addition of 4% n-propanol, 8% n-propanol, 4% n-butanol and 8% n-butanol with diesel respectively. The NO emission was decreased by 6.098%, 19.665%, 11.585% and 14.329% for the addition of 4% n-propanol, 8% n-propanol, 4% n-butanol and 8% n-butanol with diesel respectively. (C) 2014 Elsevier Ltd. All rights reserved.