Difference between 91E10 and 91 ethanol-free?

[BrandonM]

The gas station I typically use has two grades of premium, 91E10 and 91 ethanol-free. Anyone know what the difference is?

 

[Alistair D]

Hi, a quick search.....
E10 is a blend of regular unleaded (RON 91) petrol and between 9% and 10% ethanol. Ethanol-free gas can provide better performance and additional horsepower, especially in older vehicles. Ethanol contains 30% less energy than gasoline.