What criteria must a vehicle meet to pass the emissions inspection?

To pass the emissions inspection, a vehicle must not exceed the allowable limits of pollutants. This criterion is essential because the primary purpose of an emissions inspection is to ensure that vehicles are not contributing to air pollution beyond a given threshold. Such limits are set by environmental regulations to safeguard public health and the environment.

By focusing on the measurement of exhaust emissions, inspectors evaluate whether the vehicle operates within specified parameters for pollutants such as carbon monoxide, nitrogen oxides, and hydrocarbons. Meeting these standards is vital for ensuring that vehicles are environmentally compliant, thereby reducing the overall impact on air quality.

The other options do not pertain directly to emissions; for instance, while new tires or a full tank of gas might be important for overall vehicle performance or safety, they do not influence emissions levels. Similarly, a vehicle's age does not automatically determine its emissions output; older vehicles can be well-maintained and still comply with emissions standards. Thus, the correct answer is centered on compliance with pollutant limits, which is the essence of what an emissions inspection is all about.