However, because of operating losses in the induction system due to intake runner and cylinder wall wetting, a more realistic air/fuel ratio for maximum horsepower will be a richer 12.2:1 to 13.5 ...

Many have to do with the fact that a richer fuel mixture is required when an engine is cold, and even more so when it’s cold outside. Opens in new window. Skip to main content.

Richer Isn't Always Better. There are numerous ways to keep engine knock at bay when calibrating an engine for optimum performance. One is to simply run a richer air/fuel ratio.

This is necessary because the air/fuel ratio must be richer for a cold engine. Combustion is poor, and a 14.7:1 stoichiometric air/fuel ratio would cause stumbling, stalling, and poor idling in a ...

Air/Fuel Ratio. Tim Wusz:E85 requires a richer air/fuel mixture than gasoline because, ideally, we want to burn as much fuel as we can with the amount of oxygen in the air.

In the cooler months, gas mileage often decreases in cold weather due to mechanical and environmental factors. Engines require a richer fuel mixture to start and warm up, which consumes more fuel.

This also means that stomping on the go pedal of a diesel introduces a richer fuel/air mixture into the cylinder, and if that mixture is too rich without enough air mass flow, ...

In the cooler months, gas mileage often decreases in cold weather due to mechanical and environmental factors. Engines require a richer fuel mixture to start and warm up, which consumes more fuel.