Cars can only get the EPA-estimated gas mileage rating they were built for when kept in peak condition. As they fall into a sorry state of disrepair, their fuel efficiency starts to plummet. But what exactly contributes to that happening?
Would you believe that poor gas mileage simply points to the need for maintenance?
According to #savagescotty, it’s true! Services it might need include:
- Air filter replacement
- Timely oil changes
- Mass airflow sensor cleaning
- Battery replacement
- Brake service
As a part of his popular car repair series, auto tech Scotty Kilmer goes over all the services that can help everyone get the best gas mileage possible. So, follow along and learn all about the maintenance tasks that’ll keep more money in your pocket in the long run.
Scotty’s Top Reasons You Might Get Bad Gas Mileage
As a professional car mechanic and YouTube sensation, Kilmer regularly hears, “Why is my car suddenly getting worse gas mileage?” from his clients and viewers alike. So, he decided to run down the list to help everyone restore the fuel efficiency of their cars. Here’s what you need to know.
Start with the Air Filter
After hearing complaints about gas mileage, Kilmer always goes straight to the air filter. More often than not, it is clogged with dirt and debris, desperately in need of replacement. With just a quick change, the new air filter lets the car run as intended and brings fuel efficiency back into the desired range.
Skip the filters that claim to improve gas mileage, however. Scotty warns that claim is a load of nonsense and better to get an OEM filter.
Turn Your Attention to the Oil
To get the best gas mileage possible, your car needs clean oil in the right weight for its build. The weight is listed right on the oil cap or in your owner’s manual.
When you go with the manufacturer’s recommended oil weight, it reduces friction and improves fuel efficiency. According to Kilmer, heavier weight oils can easily drop your gas mileage by up to 10%.
Clean the Mass Airflow Sensor
The mass airflow sensor in your car can drop gas mileage significantly when it gets dirty or goes bad.
The sensor has tiny wires inside that give false readings as it builds up with dirt and debris.
According to Scotty, you can fix the issue by cleaning it inside with mass airflow sensor cleaner. For even more peace of mind, get yourself a cheap scanner and look at mass airflow sensor data.
Check the Battery Voltage
Weak batteries can easily destroy the fuel efficiency of your engine. Without enough voltage coming from the battery, the systems can go crazy and stop working as intended.
Kilmer lets us know that a major warning sign is an engine that will turn over but won’t start up right away. If you can get your hands on a battery system tester, that’ll show you if your battery is causing your troubles.
Get a Transmission Scan
Since the transmission directly transfers power from the engine to the wheels, poor shift performance can result in bad gas mileage. The same goes for transmissions that slip as they shift.
Whether you notice any shifting issues or not, it’s wise to have a mechanic run a scan to check the condition and operation of the transmission. If any codes come up, you can fix the problem and restore your gas mileage.
Look for Brake Drag
If your brake pads or shoes are sticking against their mating surfaces, the drag will decimate your gas mileage. To check for drag, you can just jack up all four corners and spin your wheels by hand.
Kilmer points out that if your wheels won’t spin freely or at all, then your brakes are causing significant drag. This is the same as driving with your foot on the brake pedal at all times.
Fill Up with the Right Fuel
Every car is built to use a specific kind of gas, and going against that recommendation can destroy its fuel efficiency. Most modern cars are happy enough with regular octane gas, while high-compression sports cars want higher octane levels.
By putting the wrong octane gasoline into your car, it won’t run nearly as well, often using up much more gas than normal. For that reason, Scotty urges us all to respect the recommendations and just use the right fuel for the engine in question.
Use These Tips to Improve the Fuel Efficiency of Your Car
As you go through this list from Scotty Kilmer, you’re sure to see your car’s fuel efficiency improve. After that, add to these insights about your car by looking up its Vehicle History. That way, you’ll have all the info you need to enjoy your car well into the future.
