Close this search box.


Home ➜ Community ➜ Blog

Gas Myth: Gas Mileage Drops As a Vehicle Ages

Gas Myth: Gas Mileage Drops As a Vehicle Ages

Have you found yourself fueling up at the gas station more often than ever before? There’s a good chance that your vehicle’s fuel economy just isn’t what it once was. It’s possible you’ve heard that gas mileage drops as a vehicle ages, but is that nothing but a myth? Continue on for a detailed answer from HSO!

Factors (Aside from Age) That Impact Gas Mileage

First off, let’s start by discussing several factors that impact your vehicle’s gas mileage aside from its age:

  • Speeding – Once you hit a speed of 50 miles per hour or higher, your vehicle’s fuel economy starts to drop. There is a significant decrease of about 42% when driving 70 to 80 mph.
  • Having low tire pressure – Gas mileage declines by .4% for every 1-psi drop in pressure.
  • Idling frequently – An idling vehicle wastes up to 5 gallons per hour.
  • Blasting the A/C – This can result in the gas mileage dropping by more than 25%.
  • Driving with the windows down – At highway speeds, your vehicle will have to work harder to drive in the wind.
  • Forgetting routine maintenance – Regular oil changes, coolant checks, and general engine tune ups are necessary for maintaining an optimal fuel efficiency.

New vs. Used Vehicles

Now that you know your vehicle’s gas mileage can vary, it’s time to consider how age may or may not play a role. Let’s say that you originally bought your vehicle when it was new. As the years passed, some of the factors listed above had an impact on your vehicle that led to it being less fuel efficient today. Now, let’s say that you bought a used vehicle from 2015 and it gets 25 miles per gallon today. The only real way to know what it originally got is to look up the vehicle as new online. What this won’t reveal, however, is the tendencies of the owner before you. So it’s not quite fair to say that age is to blame yet.

How It’s Made

Next, we’ll explore how vehicles are now made to have a better fuel economy. Think of the various designs and styles that sedans, trucks, and vans come in. A lighter vehicle will use far less energy than a heavier one so manufacturers consider that fact carefully. Nowadays smaller engines are turbocharged, bodies are made of aluminum or carbon fiber, and multi-speed transmissions have even replaced three- and four-speeds. This means that an older car, which was made in an entirely different way, will have a different build and ultimately a lower fuel economy. So it’s less about the actual age of the vehicle and more about the date it was produced.

Is It a Myth?

Since there are so many factors that can have a negative effect on your vehicle’s gas mileage, maintenance is key to the engine’s performance, and vehicles were built differently in the past than they are today – we’re going to say that “gas mileage drops as a vehicle ages” is a myth! By practicing good driving habits and performing routine upkeep on your engine, your fuel efficiency should remain intact for years to come.

Speaking of efficiency, HSO efficiently delivers gasoline and diesel fuel to commercial companies, construction sites, and farms. If your bulk fuel supply is starting to dip, call us at 1-800-467-5044 to schedule a delivery.




6910 Front Street. Barnhart, Missouri 63012

Phone number


Mailing Address

PO Box 9 Barnhart, Missouri 63012