The constant pressure specific heat capacity ( , , ) 0 or c p T x p s /Jkg-1K-1 of 1-butanol and Diesel fuel blends at temperatures T = (253.15 to 468.15) K are reported with an estimated average cp/cp = ±0.5% deviation. Measurements were carried out using a Perkin Elmer’s Pyris 1 differential scanning calorimetry (DSC). The excess heat capacity ( , , ) 0 or c p T x s Ep/Jkg-1 K -1 of 1-butanol and Diesel fuel blends were calculated. Polynomial equation as a function of temperature was used for the fitting of measured data,