[Hotfingrs]

Now define the word "built" Engines are built with a certain CR and to run on a certain octane...very easy to pick up HP if the engine was made to run on 94 and you start off using 87....After you pass the point of octane that your engine was made to run on, more will do you no good....as far as winter and summer gas, your engine will run cooler on summer gas...you're running more gas through the engine, thus having a cooling effect..winter gas has more oxygen, thus making your engine run hotter...just increase your jets in the winter and you won't notice a difference, might even pick up a couple of horses because of burning more oxygen......