Has anyone modeled the MPG of their hybrid versus the same routine driving with a non-hybrid? And in doing so correlate the numbers for both vehicles to their respective EPA ratings?

During the past many years, vehicles, etc. I have been able to closely model/estimate the MPG observed from the % city/highway driving and the EPA numbers. Obviously, certain factors will have short term influence but the long term averages are spot on.

Since a hybrid by design will get better city gas mileage than a non-hybrid. I was curious to see how well they correlate.