TUNING

AFR — Fuel Ratio

Definition

The mass ratio of air to fuel in the combustion mixture. Stoichiometric AFR depends on fuel: gasoline 14.7:1, diesel 14.5:1, E85 9.76:1.

Why workshops care

AFR is the "natural" way to express mixture for petrol tuners (less abstract than lambda). Same information — different units. Use the Lambda/AFR converter to switch.

Related terms

Lambda (λ)Wideband O2Lambda/AFR Converter