Motor fuel ration book and petrol vouchers from 1973. These were issued during the 1973 Arab- Israeli, or Yom Kippur, war. An oil embargo imposed on the United States by OPEC (organisation of petroleum exporting countries), for supplying the Israelis with arms, caused a massive increase in the price of oil. This resulted in petrol shortages, and although ration books were not put in to use, measures, such as reduced speed limits, were used to conserve fuel.