How To Get Better Mileage From A Diesel?

  • Turn off the engine. Excessive warm-up times can deplete diesel fuel consumption, therefore avoid idling to save money.
  • When possible, use shore power. This is also known as truckstop electrification, because it allows drivers to plug in instead of idling, which helps to keep the vehicle cool while parked. Shower power is projected to save as much as $3,240 per year!
  • The engine should not be revved. Slowly transition to your next gear rather than as quickly as feasible. It’s a little less enjoyable, but it’s also a lot less expensive.
  • Find the sweet spot of your engine and ride it. Operating at the peak torque zone once you’ve reached your cruising speed provides you the most horsepower and diesel fuel mileage.
  • Make the most of your air conditioner by using it as little as possible. Running the air uses fuel, so if you can prevent it to save money, do so.
  • Be aware of approaching traffic signals. It is possible to save fuel by avoiding a complete halt. You’ll use less fuel if you can see the light is going to turn green and you can safely slow down without stopping.
  • Maintain a safe gap between you and the vehicle in front of you. The further you are from the vehicle in front of you, the less likely you are to have to stop. Stopping less also means avoiding excessive acceleration caused by braking.
  • Reduce your highway speed on a regular basis. While it may seem counterintuitive to get there faster, every mile per hour beyond 55 reduces your fuel economy by 0.1 miles per gallon.
  • Don’t slam on the brakes. To avoid fuel burn spikes, use smooth, constant gasoline acceleration.
  • Make use of your cruise control. You can avoid using the throttle to climb hills by utilizing cruise control to maintain a constant pace.
  • Use truckstops at the top of slopes if at all possible. Stopping at the top of a hill allows you to gradually return to the highway downhill, using less fuel. Alternatives can be found using the Multi Service Fuel Card truckstop locator.
  • When not utilizing cruise control, avoid accelerating excessively. Allow the truck’s momentum to carry it over the top of a hill to avoid slamming on the gas pedal too hard.

The Multi Service Fuel Card is responsible for the content on this page. Simply put, it’s the finest overall fuel card value on the market right now. We provide substantial credit lines, access to our Zero Fee and Rebate networks, industry-leading customer service, and more.

Why is my diesel getting bad mileage?

The flow of fuel into the engine might be severely hampered by a faulty fuel injector or a dirty/old fuel filter. One of the most prevalent causes of poor gas mileage is an issue with the fuel system. The more you use your air conditioner, the poorer your gas mileage will be.

Can you tune a diesel for better mpg?

“Do you have any tuner goods that can help me conserve gas and possibly get a bit more power out of my car?”

First and foremost, I like to find out if the car is mechanically okay when I speak with clients who are experiencing poor fuel efficiency. In your situation:

  • Has the truck’s suspension and steering parts been recently inspected or serviced?
  • Have the filters and fluids on the trucks been changed in a timely manner?
  • Have you checked or tested your truck’s turbo system and intercooler pipework for boost leaks?
  • Is the truck’s emissions system (EGR and DPF, if installed) working properly?

If everything seems good, we’ll move on to the truck’s present setup and driving habits.

In your instance, you’re defying all principles of aerodynamics; your truck will never attain 20 to 25 MPG since the resistance it faces is too large; your options are to go with a smaller tire size and lift or accept a lower fuel economy.

Assume you don’t have a lift or large tires, and your aerodynamics are in good shape.

Do you prefer to slam on the brakes at every green light, or do you live for the rush of a motorway on-ramp? (Of course, I’m guilty of this!)

If you answered yes, you can change your driving habits and observe an improvement.

Now, to directly answer your question, we do provide tuning products that often result in increased fuel economy. Installing a correctly crafted tune or collection of tunes will usually result in a 1-2 MPG boost.

Some people may see more, while others may see less; because to the variables described above, over which we have no influence, we cannot guarantee any increase in efficiency.

In a controlled setting, as a vehicle’s horsepower grows, it requires less throttle input to spin the tires over each time, resulting in increased fuel economy.

Should I put additive in my diesel?

While the country’s diesel fuel supply is generally reliable, it is not always consistent. When constructing and certifying diesel engines, manufacturers take into account quality swings. In general, they oppose or advise against the use of fuel additives.

“We do not advise Volvo truck owners to add additives to their diesel fuel.” If additives are required, they should be added at the gasoline supplier terminal, according to John Moore, Volvo Trucks North America’s powertrain product marketing manager.

Last year, Cummins became the first company to publicly support a fuel additive, endorsing two Power Service products, Diesel Kleen + Cetane Boost and Diesel Fuel Supplement + Cetane Boost.

“Cummins engines are designed, developed, graded, and built to certify and function efficiently on commercially available diesel fuel,” according to Josh Hahn, Cummins Filtration’s coolants and chemicals business leader. “However, Cummins acknowledges that there are low-quality fuels on the market that don’t always meet ASTM D975, and that these fuel concerns can cause a range of problems for customers, including poor lubricity, low cetane numbers, low-temperature operability issues, and injector deposits.” When pour-point depressants, wax-crystal modifiers, or de-icers are required in cold weather operations, fuel additives may be required.”

“In recent years, diesel fuel quality has become increasingly critical as engines evolve and the diesel fuel manufacturing processes change,” said Roger England, director of technical quality and materials engineering for Cummins, when the Power Service alliance was announced last year.

That’s easy to comprehend when emissions regulations tighten and engine technology advances, resulting in tighter mechanical and engineering tolerances. In summary, because fuel supply uncertainty is unlikely to improve, engine manufacturers such as Cummins are taking steps to level the playing field.

Meanwhile, Detroit Diesel says it has no additional requirements beyond current ASTM specifications, but recommends that customers take steps to ensure they are utilizing high-quality gasoline.

“While Detroit does not directly advise any brand or type of fuel additive, we recommend Top Tier diesel fuel since it addresses many of the flaws in ASTM regulations addressing diesel fuel quality,” says Jason Martin, HDEP thermodynamics and fuel map management manager at DTNA. “Top Tier is a voluntary retailer program that addresses fuel stability and lubricity, as well as detergency, water, and particles – factors that help sustain the fuel system’s performance over the engine’s lifespan, which is a contributing factor to ensuring top engine performance.”

In North America, Top Tier diesel is available from a variety of vendors. “Because shops may also offer non-additized diesel fuel or diesel that does not satisfy the Top Tier regulations,” the website warns, “always verify the dispenser.”

Do cold air intakes work on diesels?

Improved gas mileage is another advantage of installing a cold air intake on a diesel truck. Fuel is burned to generate power in an internal combustion engine. Your engine need the proper amount of oxygen to complete this process. If there isn’t enough oxygen, it could lead to higher fuel usage. Cold air intakes are designed to offer the best air-to-fuel ratio possible, which can result in increased horsepower and better gas mileage. Because you’re getting greater mileage out of your fuel, your fuel costs are likely to drop.

Why is my mpg going down?

It seems self-evident that as an automobile gets older, it gets worse and worse gas mileage. In actuality, it’s more realistic to say that cars that aren’t well-maintained have a higher chance of losing gas mileage over time. In reality, drivers who follow their manufacturer’s maintenance schedule are less likely to experience significant fuel economy drops during the life of their vehicle.

Staying on top of routine maintenance is one of the most straightforward ways to improve gas mileage. Even yet, with so many parts to consider when your automobile approaches 100,000 or even 200,000 miles, keeping up with fuel-saving maintenance can be difficult — especially when other factors such as hot weather play a role.

What should you keep an eye out for to ensure that your car keeps running like it did the day you bought it? Begin by addressing the most common issues outlined below.

Clogged or Damaged Fuel Injectors

Dirty fuel injectors are one of the most common causes of decreased fuel efficiency. The nozzles that spray fuel into each engine cylinder are known as fuel injectors. To properly mix with air and combust inside the engine, the spray pattern of a fuel injector must be extremely exact.

Consider a poorly pressured shower head: when a gasoline injector becomes dirty or blocked, it may spray fuel inefficiently. This can quickly degrade your engine’s efficiency and diminish fuel economy. The fuel injector nozzles can usually be cleaned. If internal damage is generating a faulty spray pattern, the injectors may need to be replaced.

Old Engine Air Filter

To power vehicles, engines must draw in air. Your engine won’t be able to “breathe” if your engine air filter is excessively dusty or clogged. In order to compensate, older engines would consume more fuel to maintain the same speed. In order to compensate for a blocked air filter, newer engines may perform worse.

This issue is particularly prevalent in older autos with carburetors. Engine air filters should be replaced every 15,000 to 30,000 miles, but double-check with your owner’s manual or have it checked at your next oil change to be sure.

Dirty Oxygen Sensor

Rather than carburetors, which were used in many earlier automobiles to ensure that the engine received the necessary air-to-fuel ratio for combustion, oxygen sensors have been used in all newer cars since about 1996. An O2 sensor detects how rich or lean your engine’s exhaust gases are and sends a signal to your car’s computer, which adjusts the amount of fuel that enters the engine.

According to Edmunds, a filthy oxygen sensor can create erroneous estimations, causing your engine to use too much fuel and reducing efficiency by up to 40%.

One of the most typical causes of a check engine light is a faulty oxygen sensor, which will need to be inspected and maybe replaced before the 100,000-mile mark. Thankfully, O2 sensors are relatively inexpensive to replace, allowing you to save money on gas while also lowering your vehicle’s emissions.

Clogged Fuel Filter

Gasoline filters prevent impurities in the fuel from spreading throughout the engine, causing damage to fuel injectors and other critical components. A blocked fuel filter might cause your engine to run badly by lowering fuel pressure.

Fuel filters should be changed every two years or 30,000 miles, whichever comes first, for older cars. Bring your car to your nearest Firestone Complete Auto Care for a fuel pressure test if you suspect a filthy fuel filter is the reason of your poor gas mileage.

Worn Out Piston Rings

To create compression, the piston rings in your engine cylinders form a seal against the cylinder walls. When piston rings wear down, they are no longer able to form that seal, and the engine loses pressure. As a result, fuel efficiency is a thing of the past.

Engine oil not only lubricates the piston rings, but it also improves fuel economy. The ideal option is to get your car’s oil changed on a regular basis using the manufacturer’s recommended oil type, which can be found in your owner’s manual.

Bad Ignition System Parts

Coils, spark plugs, and wires make up the ignition system, which is responsible for combusting the air-fuel mixture in the engine. It’s possible that any of these parts is malfunctioning, causing the engine to misfire. When the fuel in an engine cylinder does not ignite, it is called a misfire. Because unburned fuel cannot power your car, you will waste gas and have a lower fuel economy.

If the ignition system is to blame, you may notice rough idling, stumbling, or a general decrease in engine power. The spark plugs are the most typical cause of a faulty ignition system.

Old or Incorrect Engine Oil

It’s a frequent misconception that older cars require heavier engine oil to avoid leaks. Internal seals and gaskets grow brittle and shrink with age, thus thicker oil would be less likely to seep through the cracks, according to the theory.

Seal conditioning additives in specially formulated “high mileage engine oils” can assist aging seals become more flexible and do a better job sealing. With addition, the viscosity is slightly enhanced to aid in the sealing of worn piston rings. Thicker oil, on the other hand, generates greater resistance between engine parts, lowering fuel efficiency.

Modern engines require the use of the proper motor oil to keep them lubricated and protected. Regular oil changes with the type of oil stated in your owner’s handbook are the best way to maintain your car’s gas mileage. High-mileage engine oils may help to reduce oil leakage and consumption, but they will also lower fuel efficiency.

Dirty Mass Airflow Sensor

The amount of air flowing into the engine is measured by mass airflow sensors. The mass airflow sensor, like an oxygen sensor, gives data to the onboard computer, which uses it to calculate the proper air-to-fuel ratio in the engine and changes fuel injection accordingly. A filthy airflow sensor, on the other hand, will cause the car’s computer to incorrectly calculate the necessary air-fuel ratio, resulting in lower fuel economy or even engine stall. A specific cleaning spray should be used to clean mass airflow sensors.

Underinflated Tires

Because an underinflated tire has increased rolling resistance with the road and a somewhat smaller effective diameter, low-pressure tires are a common cause of decreased MPG. A tire pressure monitoring system (TPMS) is built into modern cars to alert drivers when their tires need to be inflated, however the alarm is only activated after a significant drop of PSI. Even if the TPMS does not yet exhibit a warning, running five PSI below required pressure causes drag and reduces fuel economy.

Regularly checking your tire pressure and adding air as needed is one of the simplest ways to maintain fuel economy. Bridgestone Ecopia tires, which are designed with fuel economy in mind, are another sensible choice. Ecopia tires have a low rolling resistance tread that helps you conserve money and fuel by reducing the number of journeys to the gas station. While it’s ideal to combine Ecopia tires with other gas-saving maintenance, the reality remains that fuel-efficient tires contribute significantly to a greener, more cost-effective ride.

Worn or Stuck Brakes

Not only is driving with worn-out brake parts risky, but sticky brakes may also be lowering your MPG. For example, a stuck caliper or sticky brake pads add difficulty to your vehicle’s forward movement. Brake drag occurs when your engine has to constantly fight with the brakes just to move, resulting in a significant reduction in fuel economy. Check your brakes on a regular basis, or bring your car to Firestone for a complete brake inspection.

Poor Alignment

If you’ve been driving for a while and your steering wheel isn’t straight, your wheel alignment is probably costing you money at the gas pump. Misaligned wheels, like low-pressure tires, add resistance to moving straight down the road. Fighting this resistance all of the time needs more effort from the engine and reduces fuel economy. Fortunately, wheel realignment is a quick and painless procedure that can be performed at any Firestone Complete Auto Care near you.

Get the Most Out of Your Gas Mileage

Whether your car needs new tires or a new fuel filter, a Firestone Complete Auto Care specialist near you can diagnose and repair any fuel issues. Make a reservation right now!

Why is my mpg decreasing?

Bad gas mileage can be caused by a variety of factors, but the basis of the problem is that your car is not functioning properly. At the very least, this inefficiency is causing your wallet some grief at the pump, as you’ll have to fill up more frequently, but it could also be a hint of a larger problem on the horizon.

Here are some the main causes for a sudden drop in gas mileage:

  • The fuel mixture and your fuel efficiency will be affected by a bad oxygen sensor or air filter in any form.
  • Spark plugs that are bad or misfiring may cause poor performance and, as a result, a loss of power, which will cost you fuel efficiency.
  • Fuel injectors or fuel pumps that are dirty, bad, or leaking will impact the fuel mixture, resulting in poor acceleration, power loss, and fuel inefficiency.
  • Use synthetic oil that will reduce friction if the oil quality is not up to or beyond your vehicle’s recommended level.
  • Tire pressure and/or alignment issues-tires with low pressure or that are out of alignment can reduce fuel economy.
  • While you’re not using the air conditioner, remember to switch it off or defrost it when you’re not using it.
  • If your vehicle is dragging to one side, this could be a symptom of a blocked brake caliper, which feels like tugging on your own cape.
  • Check out your personal driving tendencies. Have you turned into a revving machine, a more aggressive driver, or are you warming up your car more than usual because of the chilly weather? All of these habits can help you save money on gas.

Each visit and/or oil change at Fifth Gear Automotive in Lewisville, TX includes a complete evaluation of your vehicle’s systems to ensure it is running at its best. Call Fifth Gear Automotive for a full check by one of our ASE certified experts if you are experiencing any of these symptoms.

Fifth Gear Automotive, a family-owned independent auto repair shop, has over 100 years of experience with all domestic and import makes and models, specializing in European auto repair, and has been serving Lewisville, Highland Village, Flower Mound, Lantana, Double Oak, and the surrounding communities for over 14 years. We have one aim in mind for all of your auto repairs: complete customer satisfaction.

Does DPF Delete increase mpg?

With a factory tune, I’m confident you can gain 2mpg by removing the DPF. With a dpf deletion, if you drive 1000 miles per month and achieve 15 mpg, you’ll use 66.7 gallons of gas. You’ll consume 76.9 gallons if you drive 1000 miles and get 13 mpg with a dpf. This will save you around $46 every month.

Are diesel tuners worth it?

Will a Tuner Help Me Save Money on Gas? Yes, a tuner should theoretically improve your truck’s fuel economy by enhancing engine efficiency. The highest fuel economy advantages are often seen with tunes ranging from 65 to 90 additional horsepower. This is not the case all of the time, however.

Will a tuner increase mpg?

Is it possible to boost the performance of your diesel pickup truck with an engine tuner (chip, module, or programmer)? Yes, in a nutshell, but a more detailed explanation is required.

While aftermarket performance product makers say that aftermarket performance products can add 3-4 mpg, the real savings, if any, are highly dependent on how and where you drive. Performance goods, by definition, are intended to boost engine output. A plug-and-play Juice Attitude CS programmer from Edge, for example, is said to give 150 horsepower and 360 ft-lbs of torque to a Dodge Ram 2500 with a 6.7L Cummins engine (not advised for stock vehicles).

That’s great for smoking Corvettes off the line, but it’s not going to save you money at the gas station. Indeed, the greater horsepower may make it impossible to keep your foot off the accelerator, resulting in higher engine wear and stress on your transmission and drivetrain. Simply put, you risk reducing your truck’s lifespan, voiding the manufacturer’s warranty, and increasing your chances of being pulled over by the highway patrol.

An engine tuner, on the other hand, could be your best friend if you pull big equipment, climb mountainous terrain, or travel long distances.


Manufacturers like as Edge and Bully Dog provide a Mileage Coach to assist you evaluate, monitor, and reduce gasoline use to ensure you’re on your best behavior.

Bully Dog also makes digital watchdog gauges with speed limiter adjustments, diagnostic reader, and driving coach for Caterpillar, Cummins, Detroit, Mercedes, and Paccar engines, as well as an ECM tuner with economy tuning, economy/power tuning, and custom tuning for Caterpillar, Cummins, Detroit, Mercedes, and Paccar engines. The Caterpillar ECM tuner claims a 15 to 18 percent improvement in power and a 6 to 12 percent increase in fuel efficiency for fleet owners.

An engine tuner’s appeal is that it allows you to modify your truck in a variety of ways, from towing to off-road racing, all by flipping a switch or tapping a touch screen.

For example, the Edge Juice has six on-the-fly power levels (25 hp, 70 ft-lbs; 40 hp, 90 ft-lbs; 50 hp, 120 ft-lbs; 65 hp, 160 ft-lbs; 80 hp, 200 ft-lbs; and 150 hp, 360 ft-lbs), as well as a stock (level 0) setting when necessary. It has a 4.3-inch touch screen and an optional backup camera for simple trailer attachment.

The TS Performance Stryker Injector Duration module promises up to an additional 135 horsepower and 200 ft-lbs of torque, as well as 3-4 mpg benefits.

Engine tuners, as the name implies, tweak your vehicle’s computer settings for best performance, such as injection timing, fuel/rail pressure, and injector pulse width.

Engine tuners range in price from around $350 to several thousand dollars for Class 8 truck models, depending on the bells and whistles you want.


Jason Maki, owner of K & S Service Center in Weston, Wisconsin, provides a full line of Edge, Bully Dog, and H & S Performance diesel engine performance items.

“They all do different things,” he explains. “You get a bit more efficiency, a little more performance, and a little more economy.” And it is exactly what the majority of folks are seeking for.

“Diesel performance was a significant market in the late 1990s and early 2000s,” Maki recalls. “With simply a programmer, a module, or a chip, someone could get 50, 80, 100, or 140 horses out of their truck.” However, once you reach those higher horsepower levels, you’ll run into problems.

“You normally don’t see a problem for guys just seeking for economy, but for guys who want enormous power, you wind up having to do extra work on the engine and transmission.”

Even if today’s tuners are compatible with modern diesel emission systems, Maki claims that higher pollution rules, such as the usage of urea and diesel particle filters, have reduced demand for performance items in recent years. Keep in mind, however, that removing an emission system is unlawful unless the vehicle is being used off-road.

Maki has an engine tuner in his 2014 Dodge Ram 2500 with 6.7L engine, largely for additional efficiency, and claims that performance programmers can add a few miles per gallon and roughly 50 horsepower even with today’s tighter pollution rules.

Is it really worth spending $350 for a modest increase in fuel economy, especially with today’s lower fuel prices?


“He adds, “It depends on what you’re doing.” “Probably not if you’re just running around town. However, if you drive a lot of miles or travel for work, these devices can be useful. If you gain 2 miles per gallon and drive 500,000 miles, it adds up.”

Maki, a Cummins dealer, warns truck owners that installing an engine tuner may violate their warranty.

“He says, “We let them make that decision.” “But once they’re out of warranty, anything goes.”

Most engine tuners include a cable that may be run up the door seal to a window-mounted monitor and plug into the vehicle’s onboard diagnostics port beneath the driver’s side of the dash. It takes roughly 15 minutes to complete the installation.

When changing tire sizes, tuners can be utilized for engine diagnostics, performance testing, and speedometer calibration. They can also be updated via the Internet.

Maki advises speaking with a local dealer before purchasing an engine tuner on the internet.