Corn and hazelnut oil biodiesels were produced by using methanol (CH3OH) and sodium hydroxide (NaOH), and blended with commercially available Ultra Force Euro diesel fuel at the volume ratios of 5,10,15, 20, 50 and 75%. The kinematic viscosities of the prepared blends at temperatures of 10, 20, 30 and 40 degrees C were measured by following DIN 53015 standard. The effects of temperature and biodiesel fraction on the ldnematic viscosities of the blends were assessed. New two-term power models were derived to estimate kinematic viscosities of the blends. The models were also fitted to kinematic viscosities of different biodiesel-diesel fuel blends given in literature, and compared to the previously presented models to determine their validities. (C) 2016 Elsevier B.V. All rights reserved.