Andy, I believe your biggest issue will be heat cycles on tires. Your data will never be able to account for your tires, no matter how you try to slice and dice the data. We have found out over the years that no matter what, you will get slower as your keep running the same set of tires. Put on a new set and you now have skewed the data from the old set. The only way your hypothesis could be proven is by running the engine on a dyno and not entering a correction factor due to temperature, air, and humidity.