Which type of vehicle is likely to have poor emissions performance?

Older vehicles with outdated emissions systems are likely to have poor emissions performance due to several factors. Emissions systems in vehicles are designed to minimize the output of harmful pollutants by using various technologies such as catalytic converters, oxygen sensors, and evaporative emissions controls. Over time, these systems can degrade or become less effective, particularly in vehicles that are not regularly maintained. Components may wear out, and electronic controls may not function as intended, leading to increased emissions of harmful substances like carbon monoxide, hydrocarbons, and nitrogen oxides.

Furthermore, older vehicles were often built with less stringent emissions regulations compared to modern standards, which means they may not have the advanced technologies that help newer vehicles to operate more cleanly. For example, many newer vehicles are equipped with systems that optimize fuel combustion and reduce the release of pollutants, which older models lack. Thus, it is the obsolete emissions technology and the potential lack of maintenance that contribute to poorer emissions performance in older vehicles.