, almost half of new vehicles produced by Chrysler, Ford, and General Motors are flex-fuel, meaning roughly one-quarter of all new vehicles sold by 2015 are capable of using up to E85. However, obstacles to widespread use of E85 fuel remain. A 2014 analysis by the Renewable Fuels Association (RFA) found that oil companies prevent or discourage affiliated retailers from selling E85 through rigid franchise and branding agreements, restrictive supply contracts, and other tactics. The report showed independent retailers are five times more likely to offer E85 than retailers carrying an oil company brand.