This project has investigated exhaust emissions from four popular Euro 4 conventional vehicles in the Swedish market. The vehicles studied are SAAB 9-5 Vector Sport Co, Volvo S V70, Opel Astra 5D 1,6 and Peugeot 307 XS 2,0 5D, and they are designed for standard commercial gasoline. Swedish commercial gasoline contains maximum 5% ethanol. Different higher ethanol blends (E43 and E17) as well as Swedish gasoline (E5) were applied on idle test, rated idle tests, NEDC, Artemis, US 06 test cycles. No evaporative emissions at different ethanol blends were tested in this project. When higher ethanol blends were used in conventional gasoline vehicles, the fuel consumption increased significantly comparing to using gasoline fuel (E5). Emissions levels varied betweed the individual vehicles. Only on one out of four vehicles the OBD (On-Board Diagnostics) system indicated an exhaust system error. In the short term, the environmental performance of the tested vehicles using high ethanol blends are better than expected, however this may not be the case if high blends are used over time. It should be noted that it is not allowed to fuel up with E85 in petrol cars. Using ethanol blends for gasoline vehicles may lead to aggressive deterioration of the engine and vehicle components, which over time worsens the performance of the vehicle and may render the vehicle warranty invalid. We know that vehicle emission performance differs from one model to another depending on vehicle technology and strategy. Futhermore, only one vehicle individual was tested for each model in this project, and variations in emissions between different vehicle individuals can amount up to 20% even for newer vehicles. Thus measured emissons must be analyzed with caution. Different model years, fuel quality and temperature may give different results from this project.