7.3 Powerstroke Upgrades to Improve MPG (Add 5mpg)

Everyone loves the 7.3 Powerstroke, mainly because it has such few shortcomings. With that being said, no-one has ever touted the 7.3 as being a fuel efficient engine. 15.5 combined mpg isn’t anything to write home about, that’s for sure. Luckily, there are a few basic modifications that can help you add 3-5 mpg for just a few hundred dollars. 

In addition to some mod recommendations, we also have some tips and recommendations on things to avoid to help you maximize the fuel economy on your 7.3 Powerstroke. 

We're going to discuss three modifications to improve gas mileage including an air intake, tuner, and exhaust. Furthermore, we'll touch on some topics like wheels, tires, lift kits, and gearing as recommendations for what not to do to improve mpg.

Upgrades to Improve 7.3 Powerstroke mpg

• Cold Air Intake

• Tuner/Programmer

• Exhaust

• Wheels & Tires

An upgraded air intake, a tuner/programmer, an exhaust, and tire and wheel adjustments are all ways to improve the gas mileage on most turbo diesel trucks, including 7.3 Powerstroke-equipped Fords. While there are other ways to improve fuel economy, we’ll mainly be focused on the upgrades that provide the best value for money. There is a point of diminishing returns where the cost of the mods hardly justifies the fuel saved on diesel. 

BP Intake Upgrade: 1-2mpg Improvement

Most people get an upgraded air intake for the fun sounds, but quality intakes offer much more than that. One of the least talked about benefits of an upgraded air intake is the improvements that it can make towards fuel economy. An intake can increase air density entering the engine. The denser the air, the less fuel is required to ignite it. Therefore, upgrading the restrictive stock intake on the 7.3 Powerstroke with a higher flowing performance air intake will lead to better mpg.

That isn’t to say that an intake is going to turn your truck into a Prius, though. In most cases, an upgraded Powerstroke intake can boost fuel economy by 1-2 mpg. Regardless, that is a pretty good return for a couple hundred dollars. The majority of the benefit comes from highway driving. Gains in city driving will be a lot less noticeable so the highway is where you will really see it. 

At $299, it only takes about 10,000 miles of driving for our Boosted Performance 7.3 Powerstroke intake to pay for itself and start putting money back in your pocket. You'll also get better turbo spool, quicker throttle response, and some moderate power gains all at the same time as getting better gas mileage. It's a great all-around modification.

Purchase our Boosted Performance 7.3 Powerstroke Intake

SCT X4 7.3 Powerstroke Tuner: 2-3 mpg Increase

There is quite a bit of debate in the 7.3 community in terms of the mpg gains that you can get from a tuner. While most of the manufacturer claims of 5-10 mpg gains are pretty inflated, it is certainly possible to see gains of around 2-3 mpg. 

That’s on top of some pretty noticeable power and torque gains as well. Combining an intake with a tuner is going to be the best way to maximize mileage increases you get from both the intake and the tuner.

The sweet spot of the 7.3 Powerstroke is between 1,400-1,800 RPMs at between 55 mph to about 65 mph. Some live testing has even shown up to 5 mpg gains when highway driving with cruise control at 65 mph. You are likely only going to experience around 1 mpg gains driving in the city, with the best improvements coming at highway speeds. 

Since tuners are such good value-for-money modifications, there are a ton of options available for the Ford 7.3. The best budget tuner is the SCT X4 performance tuner, hands down. It is a plug and play tuner that comes with 4 preloaded tunes, including ones for economy driving, towing, and performance. For $419, you aren’t going to find a better modification for the Powerstroke.

Purchase a 7.3 Powerstroke SCT X4 Performance Tuner Here

Upgraded Exhaust: 0.5mpg

Upgrading to a performance exhaust system is another way to pick up a bit more fuel economy while also marginally improving performance and making your truck sound significantly better. If you are looking for fuel economy modifications exclusively, an exhaust probably isn’t for you. In most cases, you'll only see marginal gains of around 0.5 mpg. While that might not sound like much, it does still add up over time. 

With that being said, a performance exhaust does provide some other worthwhile benefits. One of the biggest reasons that Powerstroke owners upgrade their exhaust to either a 4” or 5” turbo back option is to reduce exhaust gas temperatures. That leads to improved turbo efficiency, better engine health, and increased overall reliability.  

If you are purely focused on fuel savings then you can avoid tossing on an exhaust so long as you plan on sticking with modest tuning levels. The best budget exhaust is only about $290 so it's easy to justify adding it for the EGT benefits, but the mild improvements don't quite make it worth it from a cost savings standpoint as it takes a long time to pay for itself.

Purchase an MBRP 4” Turbo Back Exhaust Here

Wheels & Tires

More of a what not to do - wheels, tires, and lift kits can have a serious impact on gas mileage. Heavier wheels and bigger tires create more roll resistance which results in worse fuel economy. Going bigger and badder here will add a lot of rotational weight. Rotational weight is a lot heavier than static weight so even just adding a few pounds of weight to each wheel can have big impacts on fuel consumption.

Ultimately, avoid bigger tires and heavier wheels if you are really trying to maximize fuel. Additionally, make sure your is always inflated to the recommended specs. Low tire pressure causes more tire to contact the road, using more gas as if you were trying to ride a bike on a flat tire. 

Gearing

Gearing is another topic that can have big implications on fuel economy. In most cases, 7.3 Powerstroke-equipped Fords came with 3.73 gearing which is a good all-around ratio for moderate towing on flat surfaces. Most Powerstroke owners who tow often and in demanding circumstances prefer lower gears like a 4.10 ratio which increases acceleration but increases engine speed while cruising which is bad for fuel economy.

So, if you are looking for better fuel economy, higher gearing, like a 3.55 ratio is the way to go. Obviously, that is only a good move for Powerstroke owners who aren’t towing frequently and don’t need aggressive acceleration off the line.

Considerations & Payoff Chart

There are some important things to remember here; it isn’t realistic to expect a 5 mpg increase under every kind of driving condition. With these mods, you’ll see the best economy gains on the highway driving at between 55-65 mph. You can’t expect noticeable gains in the city or driving on the highway above 70 mph. 

Getting better gas mileage always feels good but it isn't always a great investment. If you're looking for some added power anyway then the improvements are just an added benefit. If you are purely looking for the fuel savings then you need to consider the cost, how much you drive, and whether most of your driving is highway or city.

Here is a helpful breakdown on the payback period on purchasing these upgrades:

 

The numbers above are assuming a few things. First of all, you are gaining an average of 3 mpg at all times over the payback period. They are also assuming that you are driving at least 18,000 miles per year. If you drive less than that, the payback period will be longer and if you drive a lot more than that, the payback time could be a lot less. If both of those things are true, you should be able to make your money back in around a year and a half. 

Considering that the majority of 7.3 Powerstroke Fords make it past the 300,000 mile mark, a year and a half really isn’t much of a time commitment.