E5 is a standardized gasoline blend containing up to 5 percent anhydrous ethanol by volume. The low ethanol content allows it to be used in nearly all conventional internal combustion engines without modification to the fuel system or engine mapping. In many regions, it serves as the baseline unleaded petrol grade, though higher ethanol blends are displacing it to meet renewable fuel mandates.
Heard on the job
The older pumps are still dispensing E5, but we're switching the main underground tanks to E10 next month.