HIGH COMPRESSION CARS: OCTANE REQUIREMENT AND FUEL ECONOMY.

Considerable savings in gasoline consumption can be envisaged if high compression ratio (CR) vehicles and matching gasoline of high octane number (ON) are introduced. Use of 8. 5:1 CR engine would result in an improvement of 6. 8 per cent in full economy and 9. 0:1 CR in an improvement of 8. 6 per cent. On the other hand, engines of 8. 5 and 9. 0:1 CR would require gasolines of 93 and 96 research octane number, respectively, which would also cost more than the present gasoline of 83 ON.