The biggest reason I'm building a MB is to save money on gas. I'm still going to mod it so that I can go fast if I want to However, what's the ideal rpm range for fuel efficiency? Obviously if I'm WOT at 35mph all the time, gas mileage is going to be less than ideal (and engine life for that matter). Has anyone ever done any paper work or tests to see what the ideal rpm range/speed is for fuel efficiency on a 66cc engine? Understandably, various factors must go into the equation, like rider weight, sprocket size, etc; but has anyone ever done the math with their own setup? I'm highly curious. Cheers.