According to the American Trucking Association, drivers who practice fuel-efficient driving techniques use about 35% less fuel than those who do not.
Typically, fuel is the largest operating costs in a trucking company and the average truck today can consume more than 20,000 gallons of fuel a year, costing more than $70,000.
Multiply this by the number of vehicles in a fleet and you can grasp the importance of fuel efficiency for your employer.
Beyond using aerodynamic kits, saving fuel is not that difficult and slight modifications can help you achieve greater efficiency.
The secret of good fuel economy requires overcoming:
- Rolling resistance
- Air drag
- Gravitational pull, and
- Unintentional wastefulness
Below are proven techniques that drivers have used to improve fuel efficiency. Whatever kinds of loads you haul and wherever you normally travel, these fuel saving techniques will help you reduce the amount of fuel you burn.
Overcoming Air Drag
Air drag is the result of forces pushing back against the vehicle as it passes through the air and depends on speed, frontal area exposure, and external vehicle shape.
Air resistance is the most significant contributor to vehicle power requirements, especially over the speed of 50 mph.
Minimizing the height of the load will save fuel by reducing the air drag on the vehicle. Most tractor trailers have roof mounts that deflect airflow over the highest point at the front of the trailer load.
For approximately every three feet of frontal exposure of the trailer exposed to airflow, the fuel consumption will decrease by 0.1 mpg.
In addition to overhead deflectors, we see devices that seal the gap between the tractor and trailer, sealing the trailer underbody, and trailers adding a boat tail. These aerodynamic devices can reduce the horsepower required to move the truck by as much as 35 horsepower.
Fleets looking to streamline their vehicles will need to go through some trial and error to find a good fit. Once the aerodynamic devices have been installed, follow recommended upkeep and inspections on these devices.
Overcoming rolling resistance
As the second most significant contributor to vehicle power and fuel consumption, rolling resistance is the energy required to maximize the movement of tires on a roadway.
The factors that influence rolling resistance include:
- tire pressure,
- tire tread wear,
- vehicle speed, and
It has been demonstrated that checking tire pressure regularly and keeping an eye on tread wear can achieve up to 0.5 mpg as losing 10 pounds of tire pressure can lead to a 1% decline in fuel economy.
Speeds above 50 mph lead to more friction on the roads, higher tire temperatures, and reduced fuel economy. This leads to a decrease of 0.1 mpg for every mile per hour over 55 mph.
Overcoming gravitation pull
Overcoming or utilizing gravity to your advantage is most important during steep grades. When moving a loaded vehicle up a grade, the only variable you can influence is speed.
To improve fuel efficiency–in rolling terrain–use a light throttle and allow momentum to carry the vehicle over short grades.
In hilly and mountainous terrain, use the engine’s entire operating range before gearing down, where possible.
When cresting steep grades, use gravity to bring the vehicle back to the desired cruising speed.
Also, the type of cargo you haul and how heavy it is significantly affects fuel consumption. If the cargo is distributed correctly, the engine works less. So, do not overload any axles because for every 1,000 pound increase in vehicle weight, your fuel economy decreases by 0.5%.
You can improve fuel economy when you balance the load between your drives and trailer tandems with slightly more on your drive axles.
Overcoming unnecessary wastefulness
No matter how many years you have been driving, it is easy for drivers to develop inefficient driving habits, which includes:
- driving with excessive speeds
- excessive idling
- operating the vehicle in the wrong gear, and
- harsh acceleration or braking
It is the driver’s goal to arrive on time while incurring the least expense. Below are five ways to decrease wasteful driving habits.
Number one: Warming up the engine
The most underutilized fuel savings device on the truck is the engine. When your engine is not operating at peak efficiency, there will be fuel loss.
To optimize engine economy, you need to:
- conduct routine engine performance checks
- regularly check your engine’s fluid levels (motor oil, coolant, and lube oil levels)
- check to see if there are any fluid or grease leaking
- check for worn hoses, electrical lines, belts, and inspect the air compressor
Coolant and lube oil operating temperatures can contribute greatly to fuel efficiency. Low coolant temperatures indicate the engine is too cold for efficient combustion. Lube oil below ideal temperature is more viscous and harder to pump. Oil above ideal temperature is too thin to lubricate properly.
An engine that is starved for air or unable to expel exhaust will lack power and waste fuel. Excessive fuel line restrictions will also reduce your miles per gallon.
When it comes to idling, today’s engine oils do not need you to warm up and idle your engine. Idling does not maintain the correct engine temperature and will dump oil into the exhaust manifold and turbo charger where it gets wasted.
In fact, idling can be harder on the engine than shutting it off or starting it up and can cost $3,500 or more in fuel per year.
As soon as the engine is running smoothly, you can head out slowly at first as the higher RPMs, the more fuel you will use.
Line-haul trucks not equipped with auxiliary power units might idle about 20-40% of the time the engine is running. If your truck does not have idle-reduction equipment:
- Keep the heater or A/C off when not in your truck, then turn on the truck and do a pre-trip inspection so the cab is comfortable again
- Turn off the engine whenever possible as idling longer than 10 seconds uses more oil than turning the engine off and back on
- Use auxiliary heaters or fans in milder weather
Speed & Following Distance
Traffic conditions have a significant effect on fuel use. Every time you drop down a gear, fuel consumption increases. The more you brake, speed, or accelerate, the more fuel will be used.
When possible, using cruise control will help you optimize the amount of fuel needed for any given situation, thus improving fuel efficiency.
Be sure to allow at least 6 seconds between you and the vehicle in front of you, when possible. This will help you reduce the amount of times you need to fluctuate your speed.
Topping off your fuel tank
Over filling your fuel tank can overwhelm the evaporative system and could cause leaks due to excessive pressure in the system.
Since fuel expands when it is hot, the only way for the fuel to escape is through the breaker vent.
So, prevent topping off your fuel to increase fuel efficiency.
As you might have seen from the Mythbusters television show or UPS delivery statistics, avoiding left-hand turns conserves fuel, saves time, and avoids collisions.
UPS showed they could save over three million gallons of fuel with this technique.
When mapping out your last-miles off the highway, looks for ways to reduce left-hand turns.
Create a Driver Scorecard from ELD data
ELDs gather millions of data points that include dates, time, longitude, latitude, engine power status, odometer, engine faults, critical events data, harsh braking, hard turning, hard acceleration, HOS violations, idling, speeding, and more.
Many ELD providers, including our partner Pedigree Technologies, have created driver and safety scorecards that are easy to set-up, manage, and pull reports.
For example, Pedigree driver and safety scorecards include stats, such as:
- # of HOS violations
- Idling > 20min
- Idling %
- Hard Braking event
- Speeding > 5mph
- Fuel Efficiency
- Heavy Acceleration event
These scorecards are point-based starting at 100 points and any selected stat can remove a certain amount of points based on the severity of the stat you are including in the scorecard. They can be customized further by adding a timeframe duration of the stat or distance traveled.
For example, a driver can lose 15 points for every time a hard-braking event happens every 100 miles.
Scorecard reporting can be customized by timeframe (the previous 7 days or month), selected vehicle or vehicle types (semi/long-haul trucks, medium-sized trucks, construction vehicles, etc), and more.
The Pedigree ELD reporting tool also shows if the driver has performed better or worse over the previous week or month.
Does your ELD provider offer similar reporting tools? If not, learn more about Pedigree Technologies.
DOT Compliance Programs (PSM)
At CNS, our DOT Compliance Programs focus on Proactive Safety Management (PSM), a mindset that will ensure your fleet’s safety and compliance is always in order and ahead of the FMCSA.
Our PSM Motor Carrier Program includes:
- ELD management
- Driver Qualification File Management
- New driver on-boarding
- Driver safety meetings
- CSA score management
- Policies and handbooks
- Vehicle maintenance
- and more