A vehicles' basic configuration has a lot to do with fuel economy. A properly spec'd truck can achieve impressive miles-per-gallon performance.
Peterbilt now offers an "Engineering Best Spec" to their customers for many models and vocational applications. Visit a Peterbilt dealer today to ask them what the best spec can do for your mileage, and your business.
Click here to download the Aero White Paper
A large factor in fuel economy loss is air resistance. Many owner operators prefer a traditionally styled truck, and they tend to offer more resale value, but choosing an aero model can save 4 cents per mile or more in fuel. Aero-style trucks usually come spec'd with air deflectors included for your trucking application. If you pull a van or reefer body, the most important deflector is the one on the cab's roof. It moves air up and over the roof of the trailer, reducing drag. A full cab roof fairing that matches the height of the trailer can save up to 15% compared to running with no fairings. Peterbilt offers an aero package that includes cab extenders, (which cover some of the tractor/trailer gap), side skirts that cover the fuel tanks and battery box and smooth out the profile of the steps; and an air-dam front bumper. Putting this aero package on a traditional model truck might save 1% to 3% in fuel economy.
Components/Equipment
APU
Peterbilt’s ComfortClassTM System offers a true no-idle solution. The system is available in Peterbilt’s 70” and 63” sleeper configurations, and features a fully integrated, thermal storage system with the capability to provide engine-off heating and cooling, plus 110-volt “hotel load” power for a full 10 hours even when outside ambient temperatures reach 95 degrees. While the vehicle is in operation, the 185-amp alternator charges the power pack and starting batteries. At the same time, the electric air-conditioning compressor charges the thermal storage unit located behind the sleeper to provide cooling capacity. Under most conditions, this takes about four hours for a full charge. When the truck is shut off in hot weather and the ComfortClassTM system is activated, the power pack batteries supply power to an electric blower in the cooling unit. A thermostat regulates the driver’s desired sleeper temperature.
The patented Peterbilt ComfortClassTM System, a combination of batteries and a thermal storage cooler, provides a temperature controlled environment and the capacity to run computers, microwaves and other electronic devices in the sleeper. Fuel Efficiency – As much as an 8% improvement in overall fuel economy, which results in a significant bottom-line savings by reducing operating expenses by as much as $9,000 per vehicle per year. Lower Emissions – The system emits no exhaust emissions while in operation.
Low-Rolling Resistance Tires
Install low rolling resistance tires to improve the fuel economy of heavy-duty vehicles. Check the website of your preferred tire manufacturer for the availability of these units. Another option is super-single tires to replace the dual tires on the rear axle of heavy-duty trucks with a single tire that's not quite as wide as the sum of the two to provide a smoother ride and better fuel economy. Tire tread type greatly affects fuel economy because it helps determine rolling resistance. The least resistance is offered by rib-style tires. Most fleets try to put these at all wheel positions, at least when weather allows. Switching the drive axles to lug-type tires in winter improves traction but adds resistance, and costs 2% to 4% in fuel economy. Installing shallow rib tires on the trailer can save 6% to 14% compared to a trailer with regular ribs. Trailer tires generate most of the fuel saved, according to testing done by Bridgestone, whose tests also found that the contribution of individual axle positions to fuel economy varied with vehicle configuration.
Heavy-Duty Truck Airfoils
Airfoils can be attached to direct air over the cab and trailer and improve aerodynamics and overall fuel economy of a truck. Heavy vehicles lose a tremendous amount of energy to wind resistance and drag, braking, and rolling resistance. Such non-engine losses can account for an approximate 45% decrease in efficiency.
Trailer Side Skirts
Side skirts extending between the back of the tractor and front of the trailer improve aerodynamic performance of the vehicle, and therefore fuel economy.
Tag Axles
Tag axles reduce the weight of one rear axle as it eliminates the internal axle drive train.
Locking Fuel Cap – Anti Siphon Device
A locking fuel cap provides the driver with peace of mind and protects your fuel from theft.
Trailers
Aerodynamic trailers reduce drag, and can increase fuel efficiency. Even having rounded corners can significantly reduce load drag.
Driving Tips
Idle Reduction
Studies have shown that a typical long-haul tractor-trailer idles approximately 1,830 hours per year. Across the industry, this practice consumes more than 800 million gallons of diesel fuel annually.
Slow Down
Speed is the biggest influence on fuel consumption and fuel economy. The energy that moves a truck comes from the consumption of fuel to overcome both aerodynamic and tire rolling resistances. Aggressive driving (speeding, rapid acceleration and braking) wastes fuel. It can lower your fuel mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than fuel money. Analysis shows that reducing road speed to 60 mph from 65 can lower fuel use by about 8%. A rule of thumb established is that a reduction in speed of 1 mph equals 0.1 mpg. So a 5-mph reduction in average road speed would yield a 0.5-mpg improvement in fuel economy. Check with your dealer to see if slowing down will benefit your operation.
Maintenance Strategies
Preventative Maintenance
Regular PM-Fixing a vehicle that is noticeably out of tune can improve its fuel mileage by an average of 4 percent, though results vary based on the kind of repair and how well it is done. Fixing serious maintenance problems can improve your mileage by as much as 40 percent.
Proper Tire Pressure
You can improve your fuel mileage by around 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower fuel mileage by 0.4 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer. Maintaining the correct pressure is as important as the tires used. Tires under-inflated by 15% will cause fuel penalties of around 2.5%, and a 30% under-inflation will increase fuel consumption by 5%.
Nitrogen vs. Air
Filling Tires with Nitrogen. Click here to learn more.
Air Filters
Replacing a clogged air filter can improve your fuel mileage by as much as 10 percent. Your vehicle's air filter keeps impurities from damaging the inside of your engine. Not only will replacing a dirty air filter save fuel, it will protect your engine.
Oil
Use the Recommended Grade of Motor Oil - You can improve your fuel mileage by 1-2 percent by using the manufacturer's recommended grade of motor oil. Also, look for motor oil that says "Energy Conserving" on the API performance symbol to be sure it contains friction-reducing additives.
Engine
Adequate power for an over-the-road tractor generally means 430 or more horsepower. A 475 horsepower motor is enough to briskly climb most steep grades and will still get good fuel economy if driven right; 500 hp or more is probably excessive from a fuel-use standpoint. A good compromise is a "multi" model that boosts power and torque on upgrades and automatically cuts back for cruising. Of course most electronic controls can be "flashed" to uprate the engine, and that adds value when the truck's being sold or traded in. You can take advantage of the speed control in many of today's electronically controlled engines.
Transmissions
An automated transmission can help less skilled, less economical shifters do a better job. According so some experts, automated transmissions typically save fleets 5% in fuel use - enough to pay for the transmissions in two years.
