The influence of calcium and magnesium content of plant oil on performance and formation of deposits in plant oil pressure stoves was the objective of this study. Refined coconut oil of pharmaceutical quality was used as base for fuel blends. Enriched oils comprising four different concentrations of calcium CC and five different concentrations of magnesium MC were prepared by adding single element organometallic standards. During burning tests, the specific fuel consumption, the required frequency of nozzle cleaning and the amount of deposits in the vaporizer were measured. Deposits DEP increased as the level of calcium in the fuel blends increased to 0.17 g/kg for the control and reached 10.08 g/kg for the test fuel CC42. The same was also valid for magnesium-enriched fuel blends. However, reduced concentrations of earth alkaline lead to a higher amount of deposits with 11.94 g/kg for MC18. For CC5, CC10 and CC26 the specific fuel consumption was in a range between 0.266 and 0.294 kg/h, with CC42, being significantly reduced to 0.207 kg/h. Test fuels enriched with magnesium showed a similar behaviour, where a reduction of the specific fuel consumption for the high magnesium contents of MC18 and MC26 was observed. (C) 2009 Elsevier Ltd. All rights reserved.