How to Get Better Fuel Mileage in a 6.6 Duramax

Miles Per Gallon (MPG) refers to the measured distance that a vehicle can travel in miles. Usually, it is used to indicate a vehicle’s fuel economy.

A 6.6 Duramax is said to possess one of the best Duramax engines as issues with the previous release have been rectified. The MPG (Miles per Gallon) of a Duramax varies based on diverse factors.

There is however an expected rating that should not be missed because the lower the MPG rating of the vehicle is, the less efficient it becomes.

Therefore, to get better fuel mileage in a 6.6 Duramax is by getting a new fuel filter, upgrading air intakes, tuning for extra MPG, load reduction, not leaving your car idle for long, etc.        

How Many MPG Does a 6.6 Duramax Get?

Depending on diverse factors, a 6.6 Duramax can get a 14 – 22 MPG variant. Usually, the higher the MPG rating, the better or more efficient a car is, and the lower the MPG rating, the worse it is.

For instance, the 2021 Sierra HD series, which includes a diesel engine at the 2500 level, can generate 445 horsepower and 910 pound-feet of torque. On average, this Duramax 6.6-liter V-8 gets 17 to 19 mpg on the highway.

Nonetheless, it is worthy to note that the 6.6 Liter Duramax is considered one of the best post-emission Duramax engines since issues with the previous system that had to do with the injection pump and the emission design have been fixed.

The 6.6 Duramax offers a less noisy ride with better horsepower, torque, and power ratings than previous engine versions.

The features of the 6.6 Duramax include; 10 quarts engine oil capacity with filter; 835 Lbs engine weight; 34 Gallons of fuel tank size; 3,250 RPM max engine speed

In sales, The Duramax™️ 6.6L V8 Turbo Diesel Engine comes with a 100,000 miles/160,000-kilometer warranty. It has been tested to survive upwards of 200,000 miles/320,000 kilometers.

Also, the powertrain of the Duramax 6.6 is designed for reliability, peak horsepower, and torque within the limits of its design.

How to Get Better Fuel Mileage in a 6.6 Duramax

There are several ways to improve the fuel mileage of a Duramax 6.6. They include;

1. Getting a New Fuel Filter

Just as it is essential to change the air filter regularly, it is equally necessary to replace your car’s fuel filter when due. Your Duramax engine needs a clean fuel filter to be at its best performance and mileage.

2. Air Intake Upgrades

Replacing the vehicle’s air filter whenever it gets dirty can help, but you can also modify your factory airbox slightly to let in more air.

To achieve this, you can use a file to smoothen the edges of the airbox before its reinstallation. Doing this will help create additional space for your filter to ingest the fresh air.

3. Tuning For Additional MPG

The design of diesel engines is in such a way to produce high low-end torque. At the same time, manufacturers need machines to trend towards reduced emissions. The result of conflicts like this is that manufacturers end up trading a low-end torque for torque at increased RPM.

If you can tune your truck, shifting back the torque to the low-end, you will be able to get more power while consuming less energy.

That would also translate to a significant improvement in the gas mileage. With this method, some tuning enthusiasts have claimed a 7 MPG extra.

4. Load Reduction

Another way to improve mileage would be the reduction of load—the lighter the load, the lower the consumption and emissions of fuel.

The most insignificant object in a car can reduce its fuel mileage by 1 to 2 percent. An extra weight, light or excess is capable of wasting gas. So be sure you are carrying just what you need.

5. Watch Your Tire Pressure

You have to watch your tire pressure. It has been estimated that you can improve your fuel mileage to 3.3 percent by ensuring that your tires are inflated to the proper pressure. This estimate was from the U.S. Department of Energy.

A driver’s gas mileage can be lowered by 0.4 percent when there is an under-inflation of a pound per square inch of all four of the vehicle’s tires. It is, therefore, crucial to pay significant attention to this because it counts.

6. Avoid Long Idling

Don’t leave your car on for a very long time while you don’t drive. When you get to traffic that doesn’t seem to be moving fast, you can turn off your engine to save fuel.

7. Don’t On the AC

Don’t leave your AC running when you don’t need it.

Can You Tune a Diesel For Better MPG?

Yes, you can tune a diesel for better MPG. The diesel tuning will make sure the fuel economy, as well as the engine performance, is maximized.

Diesel tuning, also known as flash tuning, involves reprogramming the ECU within your car to modify how your diesel vehicle’s engine works. This is usually done to improve the vehicle’s performance.

Diesel tuning essentially involves plugging into a diesel engine’s ECU and reprogramming the settings to perform how a driver or fleet manager wants it.

Diesel tuning helps to improve a vehicle’s power, torque, and speed. Mainly, it enhances the performance of your diesel vehicle. Generally, it is used for more modern or turbocharged cars.

Tuning new vehicles is also much easier as they have more adjustment points and reduce the time needed to change ECU. Another advantage is better fuel efficiency and use, to develop your vehicle’s power.

This happens if you fine-tune fuel injection rate and time, which entices a more efficient fuel burn to create more leverage.

Final Thoughts

A 6.6 Duramax has an average MPG rate of 14-22. In order to improve a 6.6 Duramax MPG, intentional steps have to be taken, one major step is to find ways to improve the fuel mileage of the vehicle.

There are various ways through which this can be achieved and they include; getting a new fuel filter, upgrading air intakes, tuning for extra MPG, reduction of load on gas, as well the reduction of load on tires.

When you adopt these methods of improving your fuel mileage, you should see an improvement in the MPG rate of your 6.6 Duramax.