Rejetted carburetor, stock muffler, BIG windshield, and my 6'2"+ roughly 250# self will hit 80+ riding to work each day. Atrociously pathetic fuel economy, went from 68mpg down to 48mpg.
I hate commuting on the baby bike. I've put just under 5000 miles on it since mid-April of this year. I'm on my second back tire, it needs front brake pads, needs a new oil filter... but does not need an oil change, it does that all on its own, I go through a quart or better a week high speed commuting in 90+ degree, 90-100% humidity.
I did have to switch to premium with 100:1 premix 2 stroke oil added to keep the pinging under control. And I run straight 30W oil, 20W50 full sump is dry in a couple days, 10W40 in under 40 miles.
I may be a bit rougher on my late model toys than most other owners are... I'm replacing my 20 year old mini truck that couldn't hack it with a 45 year old full sized truck that can, and has, survived my ownership.