The current mileage charge is 24p per mile.

Mileage charge- How it is calculated (Correct as at June  2010)

As you may all have noticed the price of petrol is seldom stable these days. It has been decided that due to the difficulty in forecasting petrol prices, the mileage contribution shall be set on a monthly basis, and posted on the website. In future, please check the website PRIOR to the weekend walks for the most up to date price.
Please note:
The mileage charge first appears in the 1984 programme when it was 14p but I have been unable to find out from any committee papers what was the basis for this initial charge, for example, was it solely the cost of petrol or were other costs involved &, if so, what were these. Latterly the mileage charge has focused on the change (usually upwards) in the cost of petrol with the AA calculation of a 10p increase adding 1p per mile used.
Since we have no information on the original basis for the charge & the only up to date source of information on motoring costs appears to be the AA, I propose that we use the information they provide on their website & in particular, we use the running costs for cars valued between £12k - £16k (as per attached table.) The cost per mile for petrol, tyres, service labour charges & replacement parts is currently 20.17p to which I would add 1.83p as an incentive for drivers to use their cars, making a mileage charge of 22p. The charge is therefore based on current, credible information. It is also more in line with other clubs e.g. Ramblers - 20p; Health Culture - 22p.
http://www.theaa.com/motoring_advice/running_costs/petrol2010.pdf 

Stephen Thomson,
President.