SOMETHING like 30-odd years ago, the price of petrol changed from cost per gallon to cost per litre.

I thought at the time that this was nothing but a trick to fool the public into thinking that the price of fuel was cheaper than we realised we were paying.

Gary Bebbington’s letter (Warrington Guardian, September 21) highlights the point.

In a few days, the petrol he bought rose from £7.09 per gallon to £7.18 per gallon, and finally to £7.26 per gallon.

Why do we have to endure the cost per litre when we calculate fuel consumption in miles per gallon?