Car efficiency parameter

The next step is to consider the rate at which vehicle gasoline consumption varies when compression ratio, and consequently octane requirement, is raised or lowered. In the CONWAWE study (2) this is taken to be the "change in gasoline consumption (% wt)/ unit change in vehicle octane requirement (RON)" and is termed the Car Efficiency Parameter (CEP). This is assumed to remain constant over the octane requirement range 90-100 RON. 

---