This is a mixture containing less than the stoichiometric amount of fuel, equivlance ratio less then unity. Combustion of a lean mixture will result in excess oxidizer remaining in the products.
This refers to the air/fuel mixture on an internal combustion engine. A "lean" mixture means that there is not enough fuel compared to the amount of air entering the combustion chamber. Report this Word See also: Hydro Lock | Rich Mixture | HSN | LSN Added by: FalconWings
Condition in which the mixture has a ratio more than the theoretically ideal figure of 14.7 parts of air to one part of fuel vapour (measured by mass).