VTT says that it conducted the study because many Finnish people frequently claimed that fuel consumption is significantly higher with E10 than with E5 thanks to ethanol's lower octane rating.

F1 currently uses E10 fuel containing 10 per cent renewable ethanol ... Vaidya said his company has three premium fuels - 95-Octane XP95 petrol and 100-Octane XP100 petrol used in high-end luxury cars ...

In Australia, most petrol forecourts offer 91 RON regular unleaded, before stepping up to E10 (94 RON), 95 RON premium ...

Your car can theoretically use E10 fuel, but only if that fuel has an octane rating of at least 95 RON. Much of the E10 fuel sold in Australia has an octane rating of 94, not the 95 you need, so ...