Re: 80cc? Is it really? And isn't 50cc a motorcycle?
I think the important thing is to not "attract attention". If you go blasting past a cop at 40 MPH, he's gonna pull you over no matter what you got bolted to the downtube.
I have an "80", I drive it between 20-25 MPH, and I have cops pass me w/o a second look.
But I weigh 300#, so 66cc is going to pull me like 50 would a skinny dude.