The physical, chemical and fuel properties of vegetable oils were investigated in this work. Combustion heats, determined as higher heating values (HHVs), of vegetable oil samples obtained from different Turkish sources were determined experimentally and calculated from chemical analyses. The HHV (kJ g(-1)) of the oils as a function of saponification value (SV) and iodine value (IV) was calculated with the equation: HHV = 49.43 - [0.041(SV) + 0.015(IV)], for which the correlation coefficient was 0.9999. The HHVs calculated from this equation showed a mean difference of 0.0067%. (C) 1998 Elsevier Science Ltd. All rights reserved.