Some cars that run on vegetable oil leave behind a smell of a fish & chips shop but one might think that the exhaust gases can't be too good for our health. In theory yes, but proof has arrived from the Bayerische Institut für Angewandte Umweltforschung und -technik (Bavarian Institute for Applied Environmental Research and Technology, BIFA).
Their research compared Straight Vegetable Oil (SVO) that satisfied the DIN V 51605 standard to regular diesel. As a general conclusion, the SVO fumes produce half the amount of carcinogen particullates than diesel counterparts. However, and this is important, the biggest variable in this study was engine management. A poorly managed SVO engine can produce even more carcinogen pollutants than a good diesel one. Furthermore, in the worst case scenario of diesel engines with no managament at all, the cancer risk might be 30 times higher.
Does this mean that us (bio)diesel drivers should change immediately to SVO? First of all, the engine needs to be professionally converted, as has been covered in these pages a number of times. Then, the engine must be properly maintained (which applies to all engines as well). Nevertheless, the target of this study was demonstrating that the tax reduction SVO for automotion has is completely justified.
Finally, the test was conducted in quite a peculiar way: a trunk of salmonella bacteria was exposed to exhaust fumes and the index of cell mutation was examined in the microscope. Now where's that pot of mayo I've kept in the fridge since Christmas?