Yesterday was a real test for the bio-ethanol car – I drove to a meeting in Cologne and back.

This may not sound like anything special, but with Cologne being about 200km away and the car showing 409km remaining on a full tank I was a bit worried as it would be the first time that I had had to fill up anywhere else and, of course, mix the contents of the tank.

In the end though – I didn’t have to. The journey turned out to be about 370km, and even though there was a hold up on the motorway on the way home the on-board computer still calculated that I had enough fuel for 100km when I arrived home.

Of course, this is all down to the lower fuel consumption on the motorway compared to driving around the local towns. The computer worked out that I used 11.6 litres per 100km for the trip – about 2.5 less than normal and hence the extra distance available.

Another interesting fact was that Cologne now has an environmental zone in place – your car needs to display a green “fine particle disc” in order to enter the city. I didn’t see anyone actually check mine, but I did have it on display. More about that another day.