Comparison of Car Fuel Consumption Between 95E10 and 98E5 Gasoline

In order to reduce dependence on fossil fuels and mitigate climate change, commercially available fuels today are being blended with biofuels. Ethanol-gasoline blends are one of the common biofuel-blended fuels that are available worldwide. Currently, there are two blends of bioethanol-blended petrol: the 98E5 (i.e. contains 5% anhydrous ethanol by mass) and the 95E10 (i.e. contains 10% anhydrous ethanol by mass) gasoline. The 95E10 blend has been frequently claimed to have higher car fuel consumption than the 98E5 blend, and this has led drivers to use this blend instead of the more environmental friendly 95E10 blend.

Researchers from the VTT Technical Research Centre of Finland recently conducted a formal study comparing both blends in vehicle performance studies. They tested both blends in six-petrol driven cars, all compatible with the 95E10 fuel, under laboratory conditions. The volume of gasoline consumed based from the weight of fuel consumed was calculated. Results showed that the cars tested used an average of 10.30 liters of 95E10 per 100 km, as opposed to 10.23 liters of 98E5 per 100 km. The difference was 0.07 liters per 100 km in favor of 98E5 on average. This finding suggests that using 95E10 petrol, which has a higher ethanol content, increases consumption by 0.7%. Normalizing measurement results of each individual test run with observed slight scatter in actual total work done over the driving cycle yields to an adjacent overall difference of 1.0%. The empirical results were highly consistent to their theoretical value of 1.1% computed from an estimate of calorific values based on approximate fuel composition.