I have just returned from France where I did a motorway journey of nearly 900Km each way at around 130kph average speed using E5 fuel going out and E10 fuel coming back. On the way out I was averaging about 44.9mpg and on the way back this dropped to around 40.9mpg.

It is acknowledged that E10 fuel gives less mpg and in this case for me around 9% less mpg. Some of the PR from the tree huggers is a lot more optimistic.

So here's some other interesting data having just been to the garage to tank up.

E10 fuel costs round here £1.349 per litre or £6.125 per gallon.
E5 Super unleaded costs £1.419 per litre or £6.44 per gallon.

Based on my mpg figures above my cost per mile with E5 is 14.348 pence per mile and with E10 14.974 pence per mile. So whilst Super unleaded looks unappealing at 7p per litre more expensive at the pump in performance terms it would seem to be otherwise and bring advantage and lower cost per mile.

As I explained to someone if you had to make a journey of 44.9 miles then a gallon of E5 would do it but a gallon of E10 would leave you 4 miles short so you'd need to buy more fuel say 1.1 gallons.

Recognising that putting ethanol in your petrol drops performance and also has detrimental effects on the internals in the car and makes the fuel susceptible to absorbing water and hence becoming acidic and corroding, the whole thing seems unappealing and it's a no brainer as far as I'm concerned.

So the spin is that E10 fuel uses less fossil fuel in production, which is true but that's because it's effectively diluted with ethanol. You've effectively got 5% less octane in E10 v E5 and your engine needs octane not ethanol.

I feel somewhat irritated that this has gone through without proper debate or information to the public. I suggest you do some research but don't believe all you read from the tree huggers.

And remember if you have any petrol garden tools like mowers, strimmers, chainsaws they won't run on E10!

If you're concerned about running costs of your petrol car then take note - TIB.