What are HMRC's Advisory Fuel Rates? Joe Lytwyn, personal finance expert at thimbl.com, said: "HMRC's Advisory Fuel Rates are designed to reflect the average fuel cost of running a company car for business journeys." Instead, the Advisory Fuel Rates only apply to company cars. Recommended reading:What drivers should do before SeptemberWith fresh Advisory Fuel Rates expected from September, drivers are being encouraged to check that any future claims use the updated figures. It's worth noting that the September rates have not yet been published, so drivers should continue using the current HMRC Advisory Fuel Rates until the updated figures are officially released.