2 ms·Cars are only a small portion of oil use...by kobeya 9y agoCars are only a small portion of oil use...pjc50 9y ago"Transport" is most of oil use. Admittedly that includes trucks, ships and planes. http://www.globalpetrolprices.com/articles/39/ http://www.globalpetrolprices.com/articles/39/kobeya 9y agoThe vast majority of which is trucks, ships and planes.