Gas Guzzler Tax
The so-called "gas guzzler tax" is a federal tax that penalizes the manufacture of vehicles with extremely low gas mileage. It was included in the Energy Tax Act of 1978.
The regulations include a sliding scale of gas mileage. The fewer miles-per-gallon a vehicle gets, the higher the tax. Anything over 22.5 miles per gallon (MPG) doesn't get hit with the gas guzzler penalty. As of 2016, the average fuel economy in the U.S. was 24.7, so most vehicles easily top the no-tax threshold. Veyron owners really whine about this.
From there, the tax scales up, from $1,000 for cars with an MPG of 21.5 to 22.5, all the way up to $7,000 for a vehicle with an MPG of less than 12.5. Some mobile homes get gas mileage of 15 MPG, so if you buy something with less than 12.5, the vehicle might just propel itself by spouting fuel out a pipe in the back.