Energy Conservation and Fuel-Vehicle Optimization

Abstract

A recent study done by Exxon Company, U.S.A. and Exxon Research and Engineering Company has attempted to define the relationships between unleaded octane levels, compression ratio, and fuel economy. This paper will review this work which indicated a net conservation of crude oil for octane levels as high as 87 Motor Octane under certain conditions. It also tries to show that under today’s or the foreseeable future’s capital constraints, this is not an attractive route to energy independence.

When considering the efficient use of petroleum resources for vehicular transportation, one must consider the total fuel-vehicle relation. This paper will review studies of gasoline/distillate ratios carried out by Exxon Research and Engineering for the EPA.

In any study dealing with refinery economics, a large grid of assumptions is made. Without wishing to denigrate these exercises in logic, the more obvious pitfalls will be examined. These assumptions which are normally buried deeply in the cost and yield calculations are critical to the outcome of the study. Obvious examples include economies of scale, cost of refinery fuel, credits, and disposition of light products resulting from more severe processing. Unrealistic assumptions of this nature limit our ability to forecast future opportunities or problems.

In looking ahead, it is imperative that both the petroleum and the automotive industries use such tools cautiously and with the utmost concern for their technical validity.