# Why is the maximum adiabatic temperature found for an equivalence ratio a bit higher than 1?

Why does the peak adiabatic temperature usually happen for an equivalence ratio a bit higher than 1? I think it had something to do with the probability of each fuel molecule finding a corresponding oxidizer, and the fact that the molecular weight of the fuel is generally higher than that of the oxidizer.

• Just a guess, but is it because nitrogen in the air is inert, and you have to "waste" a bit of the heat from combustion to heat it up? It's a small effect, relative to the heat of combustion, so my guess is the the max temperature would be ever-so-slightly to the carbon-rich side of the equivalence ratio. – Curt F. Jul 10 '15 at 6:05