Will new spark plugs make my gas mileage better?

Yes, new spark plugs can improve your gas mileage if the old ones are worn or faulty. Fresh spark plugs ensure better combustion by igniting the air-fuel mixture more efficiently, leading to improved engine performance and fuel economy. However, the overall impact on mileage will also depend on other factors like driving habits, vehicle condition, and maintenance. Regular maintenance, including replacing spark plugs, can help optimize fuel efficiency.