From Viktoras D.:

Re: Ethanol vehicles pose health risk, study finds (April 18): Rudolf Diesel’s first engines were built to run on pure vegetable oil for the parts of World that at that time had no petrochemicals industry. Note this as one more green alternative especially keeping in mind the related prices and terms of transition to other alternatives mentioned in the article. In fact nearly any existing diesel engine can be converted to run on vegetable oil. Even running ordinary diesel engines on biodysel (mixture of ordinary diesel and vegetable oil) substantially reduces harmful emissions. Actually there are companies (I know few in Europe) that can tweak your ordinary diesel car so it runs on vegetable oil. There are also companies selling biodysel too. So what are we waiting for ?. .