The rate of capital allowances is either 100%, 18%, or 8% (before private use adjustment), depending on the rate of C02 emissions. It hasn’t been 25% for a few years (it was 20% for a bit). Alternatively the taxpayer can claim 45p per business mile for the first 10K business miles per year, 25p per mile on excess, instead of capital allowances and all running costs (petrol, RFL, servicing, MOT, insurance) except for the business proportion of finance costs (if financed). Finance costs in addition to milage rate are available only to self employed, not employees. Milage rate for self employed only available to businesses with sales below VAT reg which I gather this is.
There is also a completely new alternative system available for simplified accounting introduced since Apr 2013 allowing for flat rate expense claims and cash basis. Not beneficial for most but as well to be aware.