Want Your MPG? 10 Factors That Affect Fuel Economy

10/28/2016


One of the biggest selling points for new cars is their fuel economy. But even fuel-efficient cars can get fewer miles per gallon (MPG) under specific conditions.

So how do you maximize your car's fuel economy? Numerous factors alter how your car uses fuel, making the engine more or less efficient. These factors include how you drive as well as how you maintain your car.

In this blog, we list five driving habits and five physical vehicle characteristics that may reduce your MPG.

How Your Driving Affects Fuel Economy

The way you drive can affect your arrival times, physical safety, and gas mileage. The following five habits can have a distinct impact on your MPG. 


1. Excessive Short Trips

Your engine works at its most efficient after it warms up. When you mainly travel in short trips, your car does not have time to warm up fully and, therefore, uses more fuel overall.


2. Frequent Cold Weather Travel

During cold weather, your car engine takes even longer to warm up and so spends less time at the desired temperature for fuel efficiency. Reduce the effect that cold weather has on your MPG by following the guidelines in our blog "Way to Winterize: 8 Steps to Prepare Your Car for Cold Weather."

Keep in mind, letting your car idle to warm up actually wastes fuel rather than improving gas mileage.


3. Heavy Braking or Acceleration

Aggressive driving forces your car to switch gears at a faster rate than is optimal for fuel efficiency. EPA testing indicates that frequent, heavy braking and quick acceleration could reduce your fuel economy by as much as 33% during highway driving.


4. High Vehicle Weight or Towing Weight

When your car is loaded down, your engine has to work harder. This extra weight may come from a cargo or bike rack, heavy interior load, or trailer.


5. Speeding

It's no secret that a speeding ticket can cost you money, but the act of speeding can also use gas more quickly. When you drive 80 MPH or faster, you create higher air resistance, decreasing your fuel economy.

How Your Vehicle's Condition Alters Gas Mileage

When your engine doesn't run smoothly, your car may use more gas than usual. Physical characteristics such as those below can affect fuel economy.


1. Fuel Injector Problems

Fuel injectors control how much gas goes into the engine. A leak or other injector problem may reduce the amount of fuel reaching the engine, forcing your car to run less efficiently.


2. Oil Type

Motor oil reduces the friction in your engine and can make up to a 12% difference in your gas mileage. For your best fuel performance, use a synthetic friction-reducing option.


3. Poor Maintenance

When your car's maintenance is neglected, all of the systems run less efficiently, including those directly linked to fuel economy. For example, a clogged air filter can affect engine performance and, by extension, fuel usage.


4. Spark Plug Issues

Misfires in your spark plugs can cause problems with overall fuel usage. When the engine doesn't get enough combustion power, your fuel economy is reduced.


5. Tire or Alignment Problems

When your tires begin to wear out or your wheels go out of alignment, they may pull against the motion of the vehicle. This additional strain can reduce your gas mileage. Keep your tires inflated properly, replace worn out tires, and have your alignment checked as needed.


Pay attention to your driving habits and the health of your car to optimize the way you use fuel.