Mileage Headed Downhill? (What Causes Bad Fuel Economy?)
October 12, 2025
Name someone you know who enjoys spending a lot of money on gasoline. Yeah, me neither. That’s because it costs quite a bit to keep fueling your vehicle.
One way to save money on gas is to get good fuel economy, and most of today’s vehicles are designed to maximize your mileage. But you might find you’re filling up more frequently than you used to and are wondering what can cause your fuel economy to tumble. Here are a few possible reasons your mileage has been headed downhill.
A logical spot to start is in your fuel system. You may have a faulty fuel injector or an old fuel filter clogged with debris. Another problem might be oxygen sensors, which measure the air coming into your engine and the emissions going out. An illuminated Check Engine light may be a sign of trouble there. Plus, worn-out spark plugs can reduce your fuel economy.
Under- inflated, or over-inflated, tires can also be a cause. Make sure they’re all at the same pressure. When’s the last time you changed your engine air filter? One that’s clogged and dirty can rob you of better fuel economy. Another bandit is a dirty, leaky, or clogged exhaust system, so have it checked out by a pro.
Finally, how you drive can also mean wasted gasoline. Jackrabbit starts and speeding use more fuel than smoother acceleration. And if you often sit there with your engine idling while you’re waiting somewhere, you’re throwing fuel away. Just turn the ignition off.
Try out some of these fuel-conserving habits and they’ll pay off for you in the long-run.
Sterling Tire & Auto
34701 Van Dyke Rd
Sterling Heights, Michigan 48312
586-264-7775
Need Service?
More articles from Sterling Tire & Auto
Helping Your Engine Breathe Easier
October 11, 2026
You may have heard someone tell you its time to replace your vehicles engine air filter and thought, Its OK. Ill do it in a while. While its tempting to put that off, keep in mind that having your engine air filter replaced is one of the easiest ways to maintain your vehicles performance and ef... More
Leaking Oil Isn’t Normal: When a Valve Cover Gasket Needs Replacing
October 4, 2026
Lets say you discover a little oil leak in your vehicle and you think, Its small. Its no big deal. Remember that no oil leak is ever normal, and it might be a sign that your valve cover gasket is failing. That gasket is what seals the top of your engine. It keeps oil inside while your engine ... More
Smooth Operator
September 27, 2026
Were used to bringing a vehicle to a stop and hardly noticing the engines even running when were sitting still. But sometimes you might notice it running rough when youre idling. Your vehicle is shaking, vibrating and making sputtering noises. You may even notice the tachometer on your instrum... More