Nowadays, there is a permanent need to develop alternative fuel production and combustion technologies. The general objective indicated in Directive 2009/28/EC for biofuels in Poland is application in transport 10% of renewable energy by 2020 and 20% by 2030. In Poland, it can be achieved by adding bio-components to liquid fuels. Flexible fuel vehicles are not as popular in Europe as in Brazil, so further ethanol processing is justified. The researched synthetic gasoline was obtained from bioethanol at the Ekobenz Company Ltd. in Poland. In 2008, Sasol launched its 100% synthetic jet fuel produced by CTL (Coal to Liquids).A variety of engine concepts was tested and evaluated in terms of the key criteria for use as a range extender developed by AVL Company. The Wankel engine has been selected for the vehicle prototype as the most compact and of excellent NVH behaviour. The use of this engine in light helicopters is also considered.The paper describes the combustion results of a synthetic fuel produced from bioethanol in the ETG (Ethanol to Gasoline) process. This type of fuel is totally alternative as it has no petroleum additives. The influence of some second-generation biofuels on emissions, fuel consumption and the characteristics of the Wankel engine was described. The combustion results were compared with those of gasoline. The emission test results were also presented for different mixtures of synfuels and gasoline. The tested object was a low intake, 4-stroke XR50 Wankel engine.