Air Fuel Ratio (AFR) Calculator
Calculate optimal air-to-fuel ratios for different fuel types. Determine stoichiometric values and understand rich/lean mixtures for engine performance and efficiency.
Step 1: Fuel Details
Understanding AFR
The air-fuel ratio (AFR) is the mass ratio of air to fuel present in an internal combustion engine. The stoichiometric ratio is the ideal ratio where all fuel is burned with all available oxygen. Rich mixtures (lower AFR) have excess fuel, while lean mixtures (higher AFR) have excess air.
Step 2: Additional Options
About AFR Values
Different engines perform best at different AFRs. Gasoline engines typically run at 12-13:1 for maximum power (rich) and 15-16:1 for maximum efficiency (lean). Diesel engines operate much leaner, typically 18-70:1. Always consult your engine manufacturer for optimal AFR values.
AFR Calculation Results
Calculated Air Fuel Ratio
Fuel Stoichiometric Ratio Comparison
| Fuel Type | Stoichiometric Ratio | Power AFR Range | Efficiency AFR Range |
|---|
AFR Breakdown
AFR Calculation Formula
AFR = Air Mass / Fuel Mass
To calculate the air-fuel ratio, divide the mass of air by the mass of fuel. For example: 14.7g of air divided by 1.0g of fuel = 14.7:1 AFR. The stoichiometric ratio is the ideal ratio where all fuel is burned with all available oxygen in the combustion process.
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