Stoichiometric Air-Fuel Ratios of Automotive Fuels J1829_200210

The mass of air required to burn a unit mass of fuel with no excess of oxygen or fuel left over is known as the stoichiometric air-fuel ratio. This ratio varies appreciably over the wide range of fuels—gasolines, diesel fuels, and alternative fuels—that might be considered for use in automotive engines.

Although performance of engines operating on different fuels may be compared at the same air-fuel ratio or same fuel-air ratio, it is more appropriate to compare operation at the same equivalence ratio, for which a knowledge of stoichiometric air-fuel ratio is a prerequisite.

This SAE Recommended Practice summarizes the computation of stoichiometric air-fuel ratios from a knowledge of a composition of air and the elemental composition of the fuel without a need for any information on the molecular weight of the fuel.

J1829_201503

2015-03-17

Latest

Revised

J1829_200210

2002-10-31

Historical

Reaffirmed

J1829_199712

1997-12-01

Historical

Reaffirmed