They don't pass most places with emission tests, so if your state or county does them then you may have an issue. But if you dont have emissions test and need the power then they are a good option. I am going to get one on my JT to get more power for pulling my 4500 lbs 23ft camper trailer.I know it'll void warrantly, and that it will require some beefy parts like a good drive shaft. What else is there to know about RIPP supercargers? TIA!