When you think about semi-trucks, fuel is typically not the first thing that comes to mind; and let’s face it, paying for fuel sucks. The only way to get around it is to walk. That is obviously not an option in this industry, but what we can do is make sure we are taking appropriate measures to minimize our fuel costs. In return that will keep our businesses cost down and profits up.
A lot of the same precautions that you can take with a car to achieve better fuel economy are still applicable to semi-trucks, just on a larger scale. That means things that make a small difference on a car will mean reasonable savings on a large truck, especially over time. Some of what we are talking about are things like appropriately managing your cruise speed as well as takeoff, keeping an ideal tire pressure, minimizing engine idling, regular maintenance, aerodynamic enhancements, and even what tires you have installed and what condition they are in. But let’s dive a little deeper and see just why this matters and how big of a difference they can make in your fuel savings by taking a look at the numbers.
People on the interstate tend to get frustrated when a semi-truck is holding a consistent speed lower than the flow of traffic. What they fail to realize is there are actually multiple reasons for the speed they are maintaining. One of those main reasons, especially for owner-operators, is their pocketbook. At the end of the day, each load only pays so much and every dollar in expenses takes away from your profit. Trucks do vary from model to model and between the different setups; which all play a role in the fuel economy that truck will get. Even with this in mind, on average, trucks will receive the best fuel economy between 55 and 60 mph. It is said that every 1 mph increase in speed over that can result in a .14 mpg loss in the fuel economy of that truck. That is money right out of your pocket. This not only goes for your constant speed but taking off from a dead stop as well. The more you floor it to get up to speed the worse fuel efficiency you are getting. For example, if your truck gets a fair 7.5mpg rating, with this loss you will be sitting at 7.36mpg. Over a year’s time or 120,000 miles, this will mean a difference of 304 gallons of fuel! Depending on the price of diesel, that can mean an additional $900 in fuel cost purely due to poor management of speed. The best advice here is to take it easy and plan accordingly.
While often overlooked for their importance in this equation, tires do play a vital role and in more ways than you might think. A common factor that is fairly well known with tires affecting fuel economy is the tire pressure. 110psi is the most commonly accepted pressure for the steer axle with a 12,000lb rating. The drive and trailer tire pressures tend to vary, with the most common being about 85psi. You can improve the fuel economy of your vehicle up to 0.6% on average just by keeping your tires at the proper pressure. For every 1psi your tires are low, you can lose about 0.2% in your fuel efficiency. So to examine the potential cost of this let’s take someone that should be getting 7.5 mpg; with this loss due to tire pressure alone, they are now getting 7.455mpg. Over a period of 120k miles, this will cost you an extra 96.5 gallons of fuel at a cost of around $288.53, depending on fuel prices. So, air up your tires! Not to mention properly inflated tires are much safer and will yield a longer lifespan.
The biggest issue with idling is the use of fuel and additional wear and tear on the equipment while not driving. As is commonly said in trucking, “if you’re not driving you’re not making money”. However, while idling you are still spending money on fuel usage. Most trucks find a sweet spot in driving around the 55-60mpg area. That is where the engine burns fuel with the most efficiently which is due to the RPM range the engine is holding at that speed. When the engine is idling it is not running at that ideal RPM range which means it is running less efficiently and costing your more. Idling a heavy-duty truck consumes about 0.8 gallons of fuel per hour which also lowers your mpg rating as you are not covering any distance for that usage. Idle varies quite a bit between trucks depending on the driver’s usage. This has of course been impacted greatly by the updated regulations but can still have a costly impact. A key solution for this would be to utilize an APU instead of running your truck’s engine during down times. Used APU’s can typically be found for around $7,000, which means they will pay for themselves in as little as two years with the cost savings.
This category should be a no brainier. However, you may be surprised how many people will still opt for the cheapest options in maintenance to keep the initial cost low, without considering long term costs. Have you heard the metaphor of a “being a well-oiled machine”? Well, there is very real meaning behind that saying. In fact, regularly preformed maintenance and even down to the type of lubricants you use can make a significant impact on your trucks performance and operating cost.
Lubricants are needed due to all the moving parts within the engine, transmission, and drivetrain. Using lubricants helps all the moving parts within the system, preventing them from grinding together causing excess heat, stress, and damage. Good quality lubricants can benefit your fuel economy by allowing the engine and other moving parts to move smoother with lower velocity and less friction. The less friction during the operations means less effort on the engine to push those parts, and of course, less effort results in less fuel needing to be burned to make it all happen.
There are many other tips and tricks out there to gain you a little leeway in the realm of fuel efficiency on your rig that you should definitely look into and see what all works for you and your truck the best. One of those ways that we came across is to improve your aerodynamics. This can be obtained by adding devices such as skirts, tails, and farings. Such add-ons are reported to have a potential savings of around 10% in fuel. That really adds up.