How to Improve Your Mustang’s MPG

How to Improve Your Mustang’s MPG

"Go Farther Per Dollar with these 10 Fuel-Saving Tips"

Last Updated August 18, 2023 | Meghan Drummond

Fuel economy isn’t the reason most people buy a Mustang, but nobody likes spending more time or money at the pump. Increase your Mustang’s mpg with a few of these fuel-focused driving and maintenance tips.

Fuel-Saving Driving Tips

Changing your driving habits isn’t easy, but the immediate benefits are gratifying. Besides saving fuel, many of these tips also decrease wear and tear on your Mustang.

1. Drive Smoothly

Few things negatively affect your fuel economy as much as slamming on the gas and brake over and over again. Smooth driving is easier on your brakes, your pedals, your legs, and your budget.

It’s estimated that aggressive driving can lower your fuel economy by anywhere from 10-40% (depending on mileage and vehicle).

Look farther ahead than the bumper in front of you to plan your accelerations and braking in advance.

Estimated MPG Savings: 10-40%

2. Reduce Weight

Removing excess weight is good for performance and for fuel economy. If you were to remove 100 pounds from your vehicle, you’d gain roughly the equivalent of 10 horsepower. That’s .10 off your quarter-mile time (and every little bit helps).

You’ll also gain 1% more fuel efficiency.

Estimated MPG Savings: 1% per 100 pounds

3. Use Cruise Control

Cruise control helps your vehicle maintain a constant speed. Most of the time, you’ll get more mpg as a result.

One study in Canada found that setting the cruise control saved 20% more fuel than cycling through speeds. Other studies got less significant results (most were in the single digits). But they all seem to show that cruise control saves fuel.

Estimated MPG Savings: Up to 20%

4. Leave the Windows and Top Up

When you put your convertible top down or open a window, you hear a rush of air. That’s because the aerodynamics of your car have been disturbed, causing drag. Keep your top and windows up (especially on the highways) to maximize fuel efficiency. On hot days, running the air-conditioning is more fuel-efficient anyways.

When you’re traveling slower, the effect of having your top down is less noticeable. That means leisurely Sunday drives in the neighborhood are still a good time to let your top down.

Estimated MPG Savings: Up to 14%

Yellow Mustang convertible with top down cruising on highway

5. Keep Idle Periods Short

Idling can burn up to a ½ gallon of fuel per hour. If you’re going to be in the same place for more than 10 seconds, you’ll save fuel by turning your engine off. Though starting up takes more fuel, it’s roughly equal to 10 seconds’ worth of driving. If your car has an auto start-stop feature, resist the temptation to disable it!

Estimated MPG Savings: 1-2% per half-hour

Fuel-Saving Maintenance Tips

Keeping your Mustang in good condition is a great way to save fuel while also improving your ride. Most of these are maintenance procedures you should be doing regularly anyway. Knowing it might also help your wallet is just a little extra motivation.

1. Maintain Your Engine

Driving around with your check engine light blazing isn’t just a bad idea, it’s also a good way to waste gas. Fixing minor issues with a quick tune-up can improve your gas mileage by about 4%.

But if it turns out you have a major issue, like a bad oxygen sensor, you can improve your mileage by up to 40%. As if you needed a better reason to tinker around under the hood.

Estimated MPG Savings: 4-40%

2. Inflate Your Tires

Tire pressure’s important. Not just for safety, but also for tire wear. If your tires are underinflated, you could also be throwing away gas money. On average, underinflated tires reduce fuel economy by 0.2% for every 1 psi drop. That doesn’t sound like much until you realize that most people’s tires are underinflated by around 25%. With an average recommended PSI of 32, that’s 8 psi or 1.6% less fuel efficiency. Make sure to check your tire pressure regularly, and you’ll save money on tires and gas.

Estimated MPG Savings: 1.6% per Tire

3. Use the Right Oil

In your owner’s manual, Ford recommended the right oil weight for your Mustang. By following this simple guideline, you’ll keep your engine in great shape and also increase your gas mileage. For S550 Mustangs, your preferred oil is going to be SAE 5W-20. If you were to use 10W-30 oil instead, you would reduce your gas mileage by around 2%.

Estimated MPG Savings: 2%

4. Select Aerodynamic Parts

How much you can save with good aero depends on the size of your vehicle. It’s estimated that 18-wheel semi-trucks lose 50% of their fuel to drag. On a vehicle like the Mustang, that’s going to be a lot less, but you can still pick parts to help the air keep flowing.

Adding something as simple as a cargo box can reduce your fuel economy by up to 25% on the interstate. On the flip side, adding some mods, like chin splitters, can increase your fuel economy.

The effect of these mods is going to vary based on your Mustang’s existing lines. Some studies have shown up to a 2% increase with just a chin splitter.

Estimated MPG Savings: 2+%

Sideview of black S550 Mustang with chin splitter

5. Change Your Air Filter

Technically, changing your air filter will only help gas mileage if you’re driving a Mustang with a carbureted engine. Classics, Fox Bodies, and SN95s might see as much as a 10% fuel economy improvement with a clean air filter.

EFI engines aren’t going to improve much unless their air filter is truly disgusting. You should still change your air filter regularly to preserve the performance of your engine though.

Estimated MPG Savings: 0-10%

Frequently Asked Fuel Questions

There’s a lot of great advice on how to save fuel in addition to the tips we’ve collected. There’re also some myths out there we should dispel. These are some of the most frequently asked questions about fuel and efficiency.

Does premium gas get better mpg?

No matter what vehicle you drive, you’re not going to get better mpg results from premium gasoline. Premium and regular are ratings on the octane level of gasoline. Octane ratings are also known as “anti-knock index” numbers. Higher octane gasoline has a higher resistance to engine knock. In a performance vehicle that’s capable of taking advantage of that, the result is better timing and more aggressive performance. It has nothing to do with fuel efficiency, though.

Does shifting to neutral help save gasoline?

Shifting to neutral likely has no effect on your gasoline usage. Most fuel-injected engines stop sending fuel as soon as your foot is off the gas. That means there’s no reason not to coast down a hill while you’re still in gear.

It’s also important to note that you sacrifice some control of your vehicle while in neutral. So, in addition to not saving you any gasoline, it’s also unsafe.

What’s the most fuel-efficient speed?

For most vehicles, the optimal speed is between 55 and 65 mph. That’s the point where you’ll get the best “bang for your buck” in terms of miles per gallon. Essentially, you’re looking for the sweet spot where your vehicle is in an overdrive gear and averaging around 1000 rpm. If you’re not paying attention to the speed limit though, a single ticket will cost much more than you’ll save.

Does drafting help save fuel?

Drafting is a really cool maneuver in motorsports. Professional drivers can use the vehicle in front of them to reduce wind resistance and improve their own efficiency.

If you’re not a professional driver and you’re not on a controlled, professionally maintained track, you should absolutely not be drafting. You’d have to get within 2 feet of a vehicle to draft off of it, and that’s too close. Especially at highway speeds.

Even if you’ve got the reflexes of an F1 driver, there’s no telling how good the driver in front of you is.

Is there a speed where windows should be down vs up?

The rule of thumb is that if you’re on the highway, the windows should be up. That’s usually the point at which the drag created by having the windows open is greater than the fuel lost by running the air conditioning.

Dark Blue Mustang with racing modifications

Mustangs and Gas

Mustangs aren’t often accused of being fuel efficient. There are a few exceptions though. Through the generations, some models have been crafted with an eye towards economy. The entire Mustang II generation is an example of this, though not by choice.

Modern modifications can also be used to increase the fuel economy of Mustangs. A very light Mustang equipped with a modern engine will be able to post a respectable average mpg.

For S550 Mustangs, the EcoBoost is definitely the most fuel efficient choice. With a rating of 25 mpg (combined) it’s exactly in line with the average for all vehicles in America.

With just a few of these strategies, you can get even more miles to the gallon.

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This article was researched, written, edited, and reviewed following the steps outlined in our editorial process. Learn more about CJ's editorial standards and guidelines.