What is one way to improve your car's fuel efficiency and lower emissions?

Using fuel with the correct octane rating can significantly improve your car's fuel efficiency and lower emissions because it ensures the engine operates at its optimal performance level. Each engine is designed to function best with a specific octane rating, which helps prevent knocking and allows for more efficient combustion. Using the proper fuel helps in achieving better fuel economy, as the engine runs more smoothly and efficiently, leading to reduced emissions from unburned fuel and other contaminants.

In contrast, the other options may not contribute positively to fuel efficiency or emissions reduction. For instance, higher grade fuel does not necessarily confer benefits for all vehicles, particularly those designed to operate on lower octane fuel, as the engine might not utilize the extra performance benefits. Rapid acceleration typically leads to higher fuel consumption and greater emissions, as engines use more fuel when operating aggressively. Reducing tire pressure can actually lower fuel efficiency because under-inflated tires create more rolling resistance, making the engine work harder. Therefore, choosing the appropriate octane rating for your vehicle is a straightforward and effective method to enhance fuel efficiency and mitigate emissions.