Simple Checks (Do these first):
* Tire Pressure: Under-inflated tires significantly reduce fuel efficiency. Check your tire pressure (including the spare) and inflate them to the recommended pressure listed on the sticker inside your driver's side doorjamb.
* Air Filter: A clogged air filter restricts airflow to the engine, reducing performance and fuel efficiency. Inspect the air filter and replace it if it's dirty or clogged.
* Fuel Filter: A clogged fuel filter restricts fuel flow to the engine. This is less immediately obvious but can definitely impact gas mileage. It's a relatively inexpensive part to replace and is worth considering if other checks don't yield results.
Intermediate Checks (May require some tools or mechanical knowledge):
* Spark Plugs and Wires: Worn spark plugs and ignition wires can cause misfires, leading to poor fuel economy and rough running. Inspect them for wear and replace if necessary.
* Oxygen Sensor(s): The oxygen sensor(s) monitor the exhaust gases and help the engine maintain the optimal air-fuel mixture. A faulty sensor can cause the engine to run rich (too much fuel), resulting in poor gas mileage. A scan tool can help diagnose this.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can lead to incorrect fuel delivery. Cleaning it (carefully, with MAF sensor cleaner) is often sufficient, but replacement may be needed.
Advanced Checks (Likely require professional help):
* Fuel Injectors: Clogged or leaking fuel injectors can cause poor fuel economy. This usually requires specialized tools and knowledge to diagnose and repair.
* Transmission Issues: Problems with the automatic transmission (if equipped) can significantly impact fuel efficiency. Slipping, rough shifting, or other transmission problems should be checked by a mechanic.
* Engine Compression: Low engine compression indicates problems within the engine cylinders, leading to poor performance and fuel economy. This requires a compression test by a mechanic.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's air-fuel mixture and affect fuel efficiency. These are difficult to find without specialized equipment.
Before you start:
* Check your driving habits: Aggressive acceleration, excessive idling, and frequent braking can all negatively impact gas mileage. Try to drive more smoothly and conservatively.
* Consider the type of driving you're doing: Mostly city driving will always yield lower MPG than highway driving.
Recommendation:
If the simple checks don't resolve the issue, it's best to take your Ford Explorer to a qualified mechanic for diagnosis. They can use diagnostic tools to pinpoint the problem and recommend the necessary repairs. Attempting to fix more advanced issues without the proper knowledge and tools can potentially cause further damage.
