5. Some of the relevant factors are:- (a) Unless either the petrol rations are drastically reduced, or considerable encouragement is granted, no large scale transfer to producers is to be expected. Among the possible inducements are subsidy, remission of licence duty and a preference in the release of new vehicles conditionally on conversion. (b) Transport gas producers require special fuels, namely particular types of anthracite and specially prepared low temperature carbonisation coke (see page 67 of L.