Viscosity correlations of peanut, soy, sunflower, waste vegetable oil and its biofuel mixtures with diesel are presented based on three suggested equations. Calibrated capillary viscometers are used for measurements. Temperature is changed between the range of 20 degrees C and 120 degrees C. Correlations show small standard errors based on the method of curve fitting. (C) 2011 Elsevier Ltd. All rights reserved.