The Gas Guzzler Tax (GGT) is a form of incentive-based taxation implemented by the United States Federal government to reduce fuel consumption and promote more efficient vehicles. The tax applies to new cars and light-duty trucks that do not meet the minimum federal average fuel economy standards of 27.5 mpg for cars and 22.2 mpg for light trucks typically governed by the Corporate Average Fuel Economy (CAFE) program.

The purpose of the GGT is to disincentivize the manufacture and importation of new vehicles that fail to meet the federal fuel efficiency standards. These vehicles — often referred to as "gas guzzlers" — have a negative environmental impact due to the larger amount of fuel they burn while in operation, resulting in higher emissions of carbon dioxide (CO2). The tax is applied to the manufacturers or importers of gas-guzzling vehicles, and not to consumers themselves.

SUVs, minivans, and light trucks are not subject to the gas guzzler tax, likely due to their heavier weight and larger engines, which inherently require more energy to operate compared to cars.

The gas guzzler tax was first introduced as part of the Energy Tax Act of 1978. The program was a way for the Federal government to encourage manufacturers to produce more fuel-efficient vehicles in order to reduce greenhouse gas emissions and conserve limited energy resources.

The GGT is a relatively small component of the overall revenue from taxes on vehicles, but supporters argue it plays an important role in reducing emissions and promoting more fuel efficient cars. By making gas guzzlers more expensive, the GGT can make more efficient cars more attractive to consumers, which may have an overall impact on reducing emissions.

In conclusion, the Gas Guzzler Tax is a measure that helps to reduce the number of high fuel-consuming vehicles on the roads and promote more efficient designs in the automotive industry. Taxing companies on gas guzzlers gives automakers more incentive to develop more efficient technologies, which can ultimately have a positive impact on our environment.