I suppose it is all to do with buying in bulk, adding percentages for tax etc and then splitting it down to a litre price.
would you like them to round the figure up to the nearest penny? ie 89.1 will now be 90p
A fair answer but why do it with fuel and nothing else. There must be other commodities that are traded in bulk and the price could always be rounded down.
Psychological pricing is often applied in consumer goods � 99p instead of �1; �9.95p instead of �10, etc. � in an attempt to delude the buyer that the price is lower than it appears. However, in the case of fuel, it involves the nonsensical use of a virtual 0.1 of a penny.
The original objective of this type of pricing was not to delude customers, but to force sales assistants to go to the cash drawer to give change, rather than pocketing proceeds.