After pointing out that although kerosene costs less than gasoline at the present time and is a cheaper fuel for the farmer to use, the author states that if the industry continues to construct tractors designed to use kerosene as fuel it will not be long before the cost of it is the same as that of gasoline. He argues that automotive engines should be designed to run on any liquid fuel and gives figures on the available supply of petroleum products and distillates in the world at the present time. The requirements laid down by the Government for gasoline are mentioned and it is stated that it is not possible for the oil industry to supply generally to the trade a gasoline meeting the recently adopted Government specifications which the author considers are very lenient. The possibilities of utilizing the cracking process to increase the gasoline supply are referred to but the author considers it economically sounder to develop automotive engines to run efficiently on uncracked fuel, pointing out what has been done abroad in developing the injection type of engine for airplanes, automobiles and tractors.A table giving data on practically all of the liquid fuels that have been considered in the past five or six years is presented and the advantages and disadvantages of these are brought out, together with information on the available supply. Considerable attention is paid to the possibility of utilizing the various farm-product sources of alcohol and the conclusion is reached that such utilization is not practicable under the present prices that are being paid for various products. Mention is made of a process that is being employed in Switzerland for producing alcohol from coal. In conclusion the possibilities of utilizing oil shales as a source of fuel are emphasized.After pointing out that although kerosene costs less than gasoline at the present time and is a cheaper fuel for the farmer to use, the author states that if the industry continues to construct tractors designed to use kerosene as fuel it will not be long before the cost of it is the same as that of gasoline. He argues that automotive engines should be designed to run on any liquid fuel and gives figures on the available supply of petroleum products and distillates in the world at the present time. The requirements laid down by the Government for gasoline are mentioned and it is stated that it is not possible for the oil industry to supply generally to the trade a gasoline meeting the recently adopted Government specifications which the author considers are very lenient. The possibilities of utilizing the cracking process to increase the gasoline supply are referred to but the author considers it economically sounder to develop automotive engines to run efficiently on uncracked fuel, pointing out what has been done abroad in developing the injection type of engine for airplanes, automobiles and tractors.A table giving data on practically all of the liquid fuels that have been considered in the past five or six years is presented and the advantages and disadvantages of these are brought out, together with information on the available supply. Considerable attention is paid to the possibility of utilizing the various farm-product sources of alcohol and the conclusion is reached that such utilization is not practicable under the present prices that are being paid for various products. Mention is made of a process that is being employed in Switzerland for producing alcohol from coal. In conclusion the possibilities of utilizing oil shales as a source of fuel are emphasized.