Which category of vehicles is exempt from a smog inspection?

The category of vehicles exempt from a smog inspection includes 1975 and older gasoline vehicles. The rationale behind this exemption is primarily based on the age of the vehicle and the fact that emissions standards for vehicles have changed significantly over the decades. Older vehicles, particularly those manufactured before 1976, were not subject to the same stringent emissions controls that modern vehicles must adhere to.

As a result, these older cars are often considered less impactful concerning air quality regulations compared to more recent models. The focus of smog inspections tends to be on vehicles that are more likely to contribute to air pollution, which is why the exemption applies specifically to those older models.

In contrast, 1998 and newer light-duty diesels, 1976 and newer gasoline vehicles, and rotary engine vehicles all fall under regulations that require them to undergo smog inspections due to their newer technology and potential emissions output.