What is the point of forecourts only using 40% of their available storage? I understand the "just in time" concept and cost of holding extra stock, but only using 40% seems low for such an essential product!
One possible explanation is the tanks were sized and installed in the days before ethanol. Petrol containing ethanol does not keep fresh in storage as long as fuel without ethanol. It's no accident that at the fuel storage depots, ethanol is only added at the very last minute just before the petrol is pumped into the road tankers for delivery.