The 'E' Type Forum

Just returned from a French event called the Champagne Rally....the title tells you everything. However on a 4 day trip of 840 miles on mixed roads, I have averaged 23 mpg! More than 10% up on previous consumption figures which can only be as a result of the E5 formulation. I have noticed this on others of my cars both in the UK and in Europe, but not as clearly evident.

Ethanol, by itself, decreases fuel mileage due to ethanol providing about 30% less energy than gasoline. So the higher the ethanol content of fuel, the more fuel you will have to burn to get the same amount of work out of the engine. And at a 5% content level in the fuel, any benefit it might otherwise provide would have only a very small effect on fuel mileage, nothing like +10%. So I would say the E5 formulation had little to nothing to do with your observed mileage increase. It's much more likely variables like your filling method, road conditions, how you were driving, average speed, and even odometer function account for the variation.

The E5 in the UK and France has an octane reading of 98/99 which could account for some of the benefit. Interestingly there has been some discussion on this subject in the UK press.
As a matter of interest my conclusions were done on a strict brim to brim basis on level ground on all my cars. I find it difficult to believe that all the odometers are not reading correctly too. Driving style has not changed even with the varying cars!

Stuart

Perhaps you were putting in some non-Ethanol champagne instead and that accounted for the increase?



John

Fuel consumption improves hugely when the journeys are longer.

Just sayin'.

I definitely notice a difference when using E5 99 Octane. If I use ordinary "Super Unleaded" E10 97/98 Octane, the car feels more lethargic and the mpg does seem to fall. It feels I can use lighter throttle settings on the 99 Octane all of which must add up to improved MPG.

Just back from our tour of Brittany.
Will work out the figures soon, but my MPG will be higher than usual