Flamelet models for turbulent combustion provide an approach (via the laminar flame) to include detailed flame chemistry into fluid dynamic simulations of IC engines. The flamelet model postulates that a turbulent flame is a statistical distribution of premixed, laminar flames. However. turbulence affects the laminar flames through strain (a) and curvature. The effect of positive strains (outflow condition) on counter-flow flames is evaluated by integrating the species destruction (or formation) through the flame.This integral is the net reaction per area of the flame and is compared to the integral for the unstrained flame. Strain reduces the net reaction rate per unit area. Flame stretch is a measure of the reduction in fuel consumption due to turbulent strain. Flame stretch is a property tending to slow turbulent flame speeds by the reduction in fuel consumption.