Schlick et al. (1988)evaluated the performance of a direct injection 2.59 L, 3 cylinder 2600 series Ford diesel engine operating on mechanically expelled-unrefined soybean oil and sunflower oil blended with number 2 diesel fuel on a 25:75 v/v basis. The power remained constant throughout 200 h of operation. Excessive carbon deposits on all combustion chamber parts precludes the use of these fuel blends, at least in this engine and under the specified EMA operating conditions.