Get Better Fuel Economy – Diesel Truck Fuel Economy Tips

If you want to increase the fuel economy on your diesel pickup, there are many ways you can do it.

Do you want to get better fuel economy from your diesel pickup? Here are some great tips that will help you squeeze a few extra MPGs out of your diesel powered pick up truck. Some of these tips are good for a few 10ths of an MPG, while others will give you substantially more miles out of every gallon of whatever you’re burning in there.

Tip 1 – Drive with the tailgate up. Sure, this flies in the face of everything you’ve been told about pick up aerodynamics since you were a kid, but it is true. Why does driving with the tailgate up get you better fuel economy than driving with it down? After all, when it’s down the air flows right over the roof, through the bed, and out the back. When it is up, the air slams into the tailgate, slowing down your truck, right? Wrong!

When the tailgate is raised, the air does not slam into it. What actually happens is that a rotating vortex of air forms in the truck’s bed. This vortex actually guides the air over the bed and deposits it gently beyond the tailgate, forming a nice smooth airflow over the bed and beyond. Opening the tailgate destroys this vortex, creates more aerodynamic drag, and kills your mileage.

Tip 2 – Drive and accelerate slower. Why sure, this is another one that you’ve heard since you were a kid, but this one happens to be true, and more so if your truck is jacked up into the stratosphere. Trucks are about as aerodynamic as the proverbial barn door, and the more it’s jacked up, the worse the aerodynamics are. It’s is a matter of both frontal area and a statistic called drag coefficient, which is a measure of how much resistance the vehicle presents to the air as it moves past. The combination of the two measures how hard it is to get your truck through the air. Jacking up your truck hits you with a double whammy. It increases the frontal area and makes your drag coefficient worse.

Since air resistance increases with the square of vehicle speed, relatively little air resistance at slow speeds turns into huge walls of air standing in the way of your truck at higher speeds. That means driving twice as fast will actually cause 4 times the air resistance. That means it takes 4 times more power to push your truck through the atmosphere at 70mph as it does when you’re driving 35mph. Take your foot out of it and you’ll save fuel.

Tip 3 – Clean up your act. All those tools you keep in the bed of your truck weigh a ton. Well maybe not a ton, but probably a few hundred pounds, especially since you keep them in that steel bed box. The combination is a heck of a lot of weight you’re carrying around every day. If you don’t use them all the time, remove them, or at least change the box to a lighter, plastic variety, especially if theft isn’t a concern. Every pound of extra weight you’re carrying takes more fuel to accelerate and take up hills. Even if your truck can tow 10,000 lbs, those 250lbs of extra tools you’re lugging around will still cost you money. It also burns up your brakes faster when you stop, costing you even more money. You could get .5% – 1.5% increase from this alone.

Tip 4 – Get an aerocap for the bed. This is a smooth, faired cover for the bed that extends form the top of the cab to the top of the tailgate. It significantly improves aerodynamics over the bed area. In fact, tests have revealed a 4% fuel economy improvement at only 55mph, with high speeds promising even better returns. These things must be expensive, right? Hardly, you can build one for less than $100. Even if you buy one and get it color matched for your truck, it should still set you back less than $500. Obviously you’ll have to remove it if you’re carrying anything in the bed that is too large.

Tip 5 – Conserve momentum when driving. This is one of the most effective driving techniques to increase fuel mileage. One of the reasons that hybrid vehicles deliver such outstanding fuel economy is because they recapture energy through regenerative braking. Since you can’t do that in your truck, you are going to conserve the momentum you have already built up.

There are 2 keys to accomplishing this. The first is to look far ahead when driving and anticipate when you might need to stop. Every time you use the brakes, you are turning your momentum into useless heat. That heat cost you precious fuel to get. Look at the traffic signals and traffic ahead of you. If traffic slows or the light turns red, get off the accelerator and coast. Your goal is to coast up to the light and get there after it has turned green, so you never have to stop. The same with heavily traffic situations. If traffic is slowing to a crawl or a complete stop, try to anticipate the flow, so you can slow down, but never entirely stop. In heavy traffic you’ll often be foiled by drivers cutting in ahead of you, but it is worth a try.

This technique avoids wasting the fuel it takes accelerating from a complete stop or a very slow speed, and sometimes can save you 10% depending on driving conditions.

Tip 6 – Drafting large trucks ca save substantial fuel, but can also get you killed. If you use this technique, make sure you’re not too close. Even having a large truck 100 feet ahead of you can offer substantial aerodynamic gains at freeway speeds. The problem is that at 65mph, you’re only about a second behind a vehicle at 100 feet. Thatb is about half the distance experts recommend for safe driving. Sure you can use the “I can stop faster than he can.” logic, and that may well be true when you’re talking about an 18 wheeler, but it is a big risk to take. If you do this, it is essential to be paying 100% attenuation at all times.

Tip 7 – Replace your factory air intake with a free flowing, after market unit. This reduced restriction in the intake tract, often leading to a 3% – 5% fuel economy improvement, depending on the truck you’re driving.

Tip 8 – Replace the exhaust system with a free flowing exhaust. Similar to the reasons that cause your engine to operate more efficiently when you change the intake system, you can do the same thing with the exhaust. Any time you lower the resistance, especially on a turbo charged engine, where exhaust tuning is less of a concern, you will improve fuel economy, throttle response, and hp/torque. All in all, a great deal.

Tip 9 – Maintain your truck. There is no sense in spending any money on any sort of add on if your truck isn’t operating at peak efficiency in the first place. Proper tire inflation, clean air filter, clean fuel injectors, and regularly changed oil all factor into your truck’s fuel mileage. Keeping your injectors clean is a matter of using a fuel additive at regular intervals. Crawling under your ride every few months to check on things, change the oil and lube things up isn’t a bad idea, either. A fuel additive will also help ensure there is no water in your fuel system and increase fuel lubricity, both of which are important to maintaining optimum performance. After spending 2 hours at the side of a road, in the middle of nowhere, waiting for a tow because the F-350 I was driving had gotten water in the fuel system, I can vouch for the fact that water and diesel do not mix.

Edge performance ECU

Modern electroncis have done wonders for driveability, performance and feul economy. Thankfully, you can take it even further with some minor mods.

Tip 10 – Add an Electronic Control Unit (ECU) programmer targeted at increasing fuel mileage. These days virtually all engine and transmission functions are controlled by one or more electronic processing units. So it was only natural for people to soon try and market ECUs optimized for more power and better fuel economy. There a half a dozen or more of these things on the market from such manufacturers as Hypertech, Edge, Bully Dog and Jet. You’ll not only get improved fuel mileage, you’ll typically get improved performance as well. Several of theses units let you change the tune for your application. That means if you’re towing, for example, you can set the ECU in tow mode to increase low and midrange torque. It is easy to set it back to fuel economy mode for increased fuel economy in normal driving when you’re finished towing. As an added bonus you’ll often get lower exhaust gas temperature, lower noise, and better throttle response when using these performance ECU systems.

How to Tell If Engine Modifications Pay Off

It is all well and good to spend several hundred or thousand dollars on increasing your fuel economy, but will you ever get your money back, and if so, when will that payoff arrive? It is all a matter of simple math.

Say you drive 20,000 miles per year and your truck averages 14mpg overall. That means you’ll burn about 1,428 gallons of fuel in a one year period. As this is written, the national average for diesel fuel is $3.07 a gallon. That means that you’ll spend $4,384 a year on fuel at current prices. If your modifications net you a 15% fuel economy increase, your mileage will go from 14mpg to 16.1mpg. Your annual fuel usage will drop to 1,242 gallons, costing you $3,813, and saving $571 per year. How much did your modifications cost?

If you spent $1,000 on an ECU programmer, a performance exhaust, and a free flow intake, you’ll be earning money on your modifications in only 21 months If you are going to keep your truck for longer than that, it makes sense to go ahead and install those modifications, because they will pay for themselves fairly soon, and then save you almost $600 per year. In most cases these mods not only give you better fuel economy, but added power too. It’s kind of like getting something for nothing or buy one, get one free.

To find the best deals on exhaust systems, intakes and ECU programmers for your truck click here now.

3 Responses to “Get Better Fuel Economy – Diesel Truck Fuel Economy Tips”

  1. Stanlee

    I strongly agree with 9 of the 10 tips. I used a K&N air filter for approximately 10 years until it was showing signs that it needed to be replaced. I temporarily replaced it with a new OEM-style WIX paper filter and my fuel mileage DID NOT change. A fresh OEM filter will provide plenty of air so you will get good fuel mileage. In short, if you heed Tip 2 and keep your foot backed off the throttle you will get better fuel mileage. Aftermarket air filters DO make more horsepower by providing additional air and decreasd intake vacuum under full throttle conditions, but this is not a maximum horsepower article.

    My 1997 Dodge Ram 12 valve gets 24.3 mpg routinely while driving at a reduced speed and 22.1 mpg driving 70 mph. I have well over 100,000 miles of fuel records.

  2. Good article. Concerning the drafting, one of my professors claimed that if you’re in a side wind, you can draft if you’re next to the truck (only try this on an interstate). He claimed that the side wind and the nose of the truck created a draft pocket on the downstream side. I don’t know if it works, but I figured it was worth throwing out there.


  3. When looking at any possible ROI from fuel saving mods, don;t forget to include any effects on engine life, whether adverse or positive. If yuo save fuel, but your engine life drops 10%, that needs to be factored in to the calculation.

    Similarilly, if yoiur modifications make your truck’s engine burn cleaner or cooler, and last longer, that must be entered into the equation as well.

    Has anyone put on a new chip or programmer, for instance and noticed if their engine seemed to run cleaner. Not talking about tailpipe emissions, but more on things like oil life.


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