What is one way to reduce toxic emissions from a vehicle?

Driving at lower speeds is an effective way to reduce toxic emissions from a vehicle. When a car operates at lower speeds, it tends to use fuel more efficiently, leading to fewer greenhouse gases and other pollutants being released into the atmosphere. Typically, vehicles consume more fuel—and consequently emit more harmful substances—when they accelerate quickly or drive at high speeds, as the engine works harder to maintain that speed. Furthermore, lower speeds generally translate to reduced engine stress and a more complete combustion of fuel, which helps lower the emissions of carbon monoxide, hydrocarbons, and nitrogen oxides.

The other options do not effectively contribute to reducing toxic emissions. Increasing tire pressure may improve fuel efficiency slightly, but it doesn't have a significant impact on emission levels. Using fuel additives might offer some minor benefits in terms of performance or efficiency, but these effects likely won’t lead to substantial reductions in emissions. Idling for longer periods is counterproductive, as it contributes to unnecessary fuel consumption and increases emissions, as the engine is still running without being in motion, wasting fuel and releasing toxins into the air.