How to Save Fuel on
Southern Illinois Drives
Fuel costs add up quickly—especially when your vehicle is part of your daily routine.
Whether you're simply commuting across Marion, driving throughout Southern Illinois for work, or planning a large, out-of-state road trip, better fuel economy matters. The good news is that improving gas mileage often comes down to a combination of smarter driving habits and proper vehicle maintenance.
At PMR Automotive, we help drivers understand what affects fuel efficiency and make sure their vehicle is operating the way it should—so they can drive with confidence, not guesswork.
Driving Habits That Affect Fuel Economy
Sometimes the biggest impact on fuel savings starts behind the wheel.
Avoid Aggressive Acceleration
Rapid acceleration and hard braking force your engine to work harder and burn more
fuel. Smooth starts and steady driving can make a noticeable difference over time (in
more than just your fuel mileage).
Reduce Excessive Idling
Letting your vehicle sit and idle for long periods burns fuel without getting you
anywhere. Modern engines don’t need extended warm-up time like older vehicles did.
Watch Your Speed
Higher highway speeds often reduce fuel efficiency. Even a small reduction in speed on
longer drives can help improve mileage. When you are taking long drives, cruise control
can be your friend (as long as the grounds are relatively flat). Maintaining a consistent speed instead of relying on your foot and speeding up and slowing down inadvertently helps keep fuel levels running smooth as well.
Keep Extra Weight to a Minimum
Carrying unnecessary tools, equipment, or cargo adds strain to your vehicle and increases fuel consumption. It's time to take that winter weight out of the back of the vehicle and give yourself more trunk space.
Plan Short Trips Carefully
Frequent short trips can be harder on your engine and less fuel-efficient than longer drives where the vehicle reaches proper operating temperature.
Vehicle Maintenance Plays a Bigger Role Than Most
Drivers Realize
If your fuel mileage has dropped, the issue may not be your driving habits at all. Small
maintenance issues often create larger fuel economy problems over time.
Tire Pressure Matters
Underinflated tires create more rolling resistance, which forces your engine to work harder.
Regular tire inspections help protect both fuel economy and tire life.
Dirty Air Filters Restrict Performance
Your engine needs proper airflow to run efficiently. Restricted airflow can affect performance
and fuel usage. Ensuring your engine breathes easy with a clean air filter is essential to
maintaining higher fuel mileage.
Worn Spark Plugs and Ignition Issues
When spark plugs wear down, your engine may misfire, run less efficiently, and use more fuel
than necessary. If your vehicle has hit 100k miles without a tune up, it may be a good idea to
get one. Even if your vehicle ins't misfiring, the spark plugs still do wear with time, causing a larger gap and lower efficiency.
Oxygen Sensors and Engine Performance
Faulty oxygen sensors can affect your air-fuel mixture and cause poor mileage—sometimes without obvious warning signs.
Brake Drag and Alignment Problems
If your brakes are dragging or your alignment is off, your vehicle may be working harder than it should every mile you drive. Regular brake & alignment checks keep you running efficiently and wallet friendly - beyond the MPG.
Old Fluids and Delayed Maintenance
Engine oil, transmission performance, cooling system health, and other maintenance items all play a role in how efficiently your vehicle runs. Not only that, but replacing these fluids keep their respective systems healthy and longer lasting.
A Proper Inspection Prevents Guesswork
Many drivers notice poor fuel mileage and immediately assume they need expensive repairs.
Sometimes the issue is simple.
Sometimes it isn’t.
That’s why a proper inspection matters.
At PMR Automotive, we inspect the vehicle, explain what we find, and help you prioritize what actually needs attention. No pressure. No guesswork. Just clear information so you can make the right decision for your vehicle.
Fuel Savings Start with Confidence
Better fuel economy usually isn’t about one “quick fix.” It’s about making sure your vehicle is operating correctly and your maintenance is keeping up with how you drive.
If your MPG has dropped, your vehicle feels sluggish, or you’re spending more at the pump than you should, we recommend starting with a professional evaluation.
We’ll help you understand what’s happening, what matters most, and what can help you save fuel for the long road ahead.
FAQ
Why is my gas mileage getting worse?
A sudden drop in fuel mileage can happen for several reasons. Low tire pressure, worn spark plugs, dirty air filters, failing oxygen sensors, brake drag, alignment issues, and overdue maintenance can all cause poor fuel economy.
Sometimes the issue is small. Sometimes it points to a larger performance problem.
If your vehicle is using more gas than usual, a proper inspection helps identify the real cause instead of guessing.
Can low tire pressure reduce MPG?
Yes—low tire pressure is one of the most common causes of poor fuel economy. Underinflated tires create more rolling resistance, which means your engine has to work harder to move the vehicle. That increases fuel consumption and can also shorten tire life.
Regular tire inspections help improve gas mileage and protect long-term performance.
Do bad spark plugs affect fuel economy?
Absolutely.
Worn spark plugs can cause incomplete combustion, engine misfires, rough performance, and increased fuel usage. Sometimes, your spark plugs can be worn and causing lower MPG even without any signs of an major issues or misfires. Many drivers notice sluggish acceleration or reduced MPG before realizing spark plugs are part of the problem.
Routine maintenance helps prevent these issues before they become more expensive repairs.
Can a check engine light affect gas mileage?
It depends on what the light is indicating. Your check engine light detects dozens of systems in your vehicle, picking up anything from a fuel cap being loose to a thermostat that is starting to stick to a faulty knock sensor and more.
Problems involving oxygen sensors, mass airflow sensors, ignition components, fuel system performance, and emissions systems can all reduce MPG. Even if the vehicle still feels “fine,” poor fuel economy is often an early warning sign that something needs professional attention.
Why is my car using more gas but driving normally?
Not every fuel economy problem creates obvious symptoms.
Your vehicle may still feel normal while hidden issues like sensor failures, restricted airflow, minor ignition problems, or dragging brakes quietly reduce efficiency over time.
Does wheel alignment affect fuel economy?
Yes.
Poor alignment creates additional rolling resistance and forces your vehicle to work harder while driving. This not only hurts gas mileage but also causes uneven tire wear and handling issues.
If your vehicle pulls to one side or your steering feels off, alignment may be part of the problem. Also, if you've had suspension or steering work or recently replaced your tires, an alignment is recommended to help prolong the life of your components.
How can I improve gas mileage for daily driving in Southern Illinois?
Better fuel economy usually comes from a combination of driving habits and proper maintenance.
Smooth acceleration, reduced idling, proper tire pressure, scheduled maintenance, and professional inspections all help improve MPG—especially for daily commuters driving through Marion and across Southern Illinois highways.
When should I have my vehicle inspected for poor fuel economy?
If you’ve noticed reduced MPG, sluggish performance, increased fuel costs, or a check engine light, it’s a good time for an inspection. The sooner problems are identified, the easier they usually are to prioritize and address.
At PMR Automotive, we inspect the vehicle, explain what we find, and help you understand what matters most—so you can make confident decisions without unnecessary guesswork.
Schedule an Appointment with Confidence
If you’re looking for a mechanic in Marion, IL who prioritizes accuracy, transparency, and long-term reliability, PMR Automotive is here to help.
Whether you need a second opinion or a full repair, our team is ready to get your vehicle back on the road—the right way.
👉 Schedule your appointment today: Book Here
📞 Or call: 618-998-9010