Iso-octane, n-heptane and their blends were tested in a constant volume combustion chamber to measure laminar flame speeds. The experimental apparatus was automatically controlled to enhance the accuracy and data acquisition speed. A large database of laminar flame speeds at elevated temperatures and pressures was established. From this database, laminar flame speeds of iso-octane, n-heptane and their blends were investigated and analysed to derive new correlation to predict laminar flame speeds at any blending ratio. The new flame speed model was successfully applied to these fuels with limited range of errors.