If you own commercial vehicles in the US you could be paying extra road taxes based on weight, and you can be restricted to certain areas within your state. You also have to pay an emissions and apportion taxes based on the vehicle and the miles that it drives, not based on the emissions the engine actually produces. 

Whenever someone is ready to talk about the US EPA I think I am ready to have a chat. The EPA does not believe "It is your right to modify a vehicle you own" and has arbitrary punishments with no guidelines to follow to stay legal. It's a setup for failure. Almost everyone in the industry just puts money away to wait for the EPA mafia to come knocking, breath down your neck for a few years then you give them loads of money and they go away for a couple years if you are lucky. If you are unlucky they get access to your surveillance system, watch you for a few months, maybe mix in a little entrapment, then finally kick down the doors to your business (or home in some cases) put you and anyone in your shop in handcuffs, for more than 12 hours, scan their phones and throw a pizza party in your office. Topping it all off usually leave you only with conspiracy charges (still felony), sometimes little jail time or house arrest, but you are now a felon.