You can recover all of the input VAT on the purchase but you must also apply a fuel scale charge which is a method used to account for the private usage. The charge is included in the output VAT box on your VAT return. The charge does not have to be calculated, but is taken from tables published by HM Revenue & Customs and is determined by the vehicles CO2 Emissions. The charges in the tables are amended annually (usually May 1st) to reflect the changes in fuel prices.
For example, if your vehicle has an emission rating of 160g/km CO2 the fuel scale charge would be £297 this figure is then multiplied by the VAT fraction (7/47) to find 17.5% i.e. £43.23 which must be included in box 1 for the VAT quarter. The tables increase CO2 emissions in multiples of 5. If your vehicle's emissions are not an exact multiple of 5 then you can round down to the nearest multiple. So if your vehicle's emission rating is 164g/km CO2, the fuel scale charge will still be £297 per quarter.
In some cases the charge may be higher than the total input VAT reclaimed for the vehicle. The only way to avoid the charge is to reclaim none of the input tax paid. This must apply to all vehicles right across your business. If this is always going to be the case you may, however, reclaim input VAT on business mileage only, but this will involve keeping a detailed business mileage log.