Iconic brand could ditch petrol for good One of the most well-known brands in the world could be on the verge of ditching petrol power for good. The iconic 6.7-litre V12 petrol engine has been a staple of Rolls Royce's modern line-up, but the brand is prepared to shelve it forever. It currently features in the Ghost sedan and Cullinan SUV, the latter being the most popular Rolls Royce model.