Fuel efficiency is a hot topic—especially when prices spike—but with it comes a lot of misinformation. Drivers often make decisions based on outdated advice or urban legends that can actually hurt fuel economy. To help you drive smarter, we’ve broken down 10 of the most common fuel-saving myths and explained what really works.
- Premium Gas Improves Performance in All Cars
False.
Unless your vehicle specifically requires premium fuel (usually noted in the owner’s manual), using higher-octane gas doesn’t improve performance or mileage. In fact, it could be a waste of money for most engines designed to run on regular.
Save money by sticking to the recommended fuel type for your vehicle. If you’re unsure, check with your manufacturer or mechanic.
- Coasting in Neutral Saves Fuel
False.
Modern engines are designed to use less fuel when coasting in gear compared to neutral. When coasting in neutral, you lose engine braking, which can increase wear on your brakes and compromise control.
Stick to coasting in gear for both safety and fuel efficiency—especially on hilly roads or in traffic.
- Fuel Additives Boost MPG Dramatically
Mostly False.
While some additives can clean fuel systems, most over-the-counter products offer little to no measurable improvement in MPG. The biggest improvements come from proper vehicle maintenance and driving habits.
If you’re purchasing maintenance supplies, choose reputable brands from trusted merchants like Advance Auto Parts or AutoZone, both known for reliable fuel system products.
- You Should Warm Up Your Car for Several Minutes
Outdated.
This myth stems from older carbureted engines. Modern fuel-injected engines only need 30 seconds to warm up—even in cold weather. Idling longer just wastes fuel.
Start driving gently after 30–60 seconds, especially in winter, to warm up efficiently.
- Small Cars Are Always More Efficient Than Bigger Ones
Not Always.
While compact cars often get better mileage, technology matters more than size. Many midsize hybrids or modern sedans now outperform older subcompacts due to advancements in fuel management systems and transmissions.
For example, hybrid options from travel-friendly services like Bowery Culture and Dreamline Vacations often include SUVs and sedans with excellent MPG ratings.
- Filling Up in the Morning Gets You More Gas
Partially True—but not significant.
Gasoline is denser in cooler temperatures, so technically you get a bit more energy per gallon in the morning. However, since fuel is stored underground where temperature is regulated, the real-world difference is negligible.
Prioritize lower prices and traffic conditions over time of day.
- Turning Off the AC Always Improves Fuel Economy
Situational.
Yes, air conditioning uses power, but so do open windows at high speeds, which increase drag. At city speeds, turning off the AC can save fuel. On highways, it may be more efficient to use the AC with windows up.
The smartest move? Use AC sparingly and set it to “recirculate” when possible.
- Manual Transmissions Are Always More Efficient
No Longer True.
This used to be the case, but modern automatic transmissions often match or beat manuals thanks to more gears, smart shifting algorithms, and fuel management systems.
If you’re buying a used car under budget, check real-world fuel ratings, or explore ride-sharing alternatives like TransitCore if you drive infrequently.
- Topping Off the Tank Gets You More Fuel
False—and risky.
Topping off after the pump stops can damage your car’s vapor recovery system, waste fuel, and lead to spills. Stop pumping when it clicks off automatically.
Consistently topping off can also create overpressure in your tank and affect emissions.
- Hybrids Don’t Perform Well on the Highway
Outdated.
Earlier hybrid models favored city driving, but modern hybrids are extremely efficient on highways, often outperforming traditional gas engines at sustained speeds.
If you’re shopping for a hybrid for commuting or travel, consider pairing it with long-distance planners like GlobeTrek or WanderPro to plan fuel-efficient routes.
Don’t let fuel myths steer you in the wrong direction. The best way to improve your fuel economy is through accurate knowledge, smart driving habits, and timely maintenance. Forget the gimmicks—focus on what actually works.
