Fuel Efficiency: A tortoise beats a hare, always

by Jeff Hutton

KITCHENER, Ont. – It’s a common myth in the trucking biz that more miles equal more money – industry studies tell a different story, one similar to the classic tale of the tortoise and the hare.

By slowing down and fine-tuning driving technique and equipment efficiency rather than running faster to carry more freight, owner/operators and fleet managers can improve their bottom line while helping the environment at the same time. And ironically, clocking fewer miles may also mean more bucks.

“Reducing speed and maximizing fuel economy is the key to maximizing profits,” says transportation economist Patrick Nagle from Truckers’ Business Consulting Group. “Every dollar spent on fuel comes directly out of the bottom line.”

Perhaps the greatest influence on fuel efficiency is the driver, who not only controls cruising speed, but a whole range of variables that directly impact the bottom line. Poor driving habits can send 35 per cent more fuel up in smoke compared to fuel-efficient driving techniques, according to the Technology & Maintenance Council of the American Trucking Associations (ATA).

Motivating company drivers to do this remains an area of great opportunity – only 24 per cent of Canadian fleets measured in FleetSmart’s Fuel Efficiency Benchmarking study had driver incentive programs. However, 70 per cent delivered some form of driver training in fuel efficiency.

FleetSmart says there are a number of ways to boost efficiency. It estimates the use of cruise control will improve fuel economy by up to six per cent, for example.

There are other truly professional driving practices that could mean extra dollars in both the bank and the tank:

Stay calm

Relax. Be happy.

“Often we can spot when a trucker has had a fight with his wife, since we see his fuel costs go up,” says Patrick Nagle. “Most people drive more aggressively when distressed, and the ‘heavier foot’ shows up in reduced fuel efficiency.” – TBC Group.

“Attitude is the most important of all … anything that makes the driver ‘mad’ at the truck: steering wheel pull, high noise, uncomfortable seating, poor temperature control, vibration, etc. decreases driver motivation and thereby increases fuel use.” – The Fleet Manager’s Guide To Fuel Economy by the Technology and Maintenance Council of the ATA.

Progressive thinking

Use progressive shifting, “To reduce fuel consumption by eight per cent or more. Shifting before you reach the maximum governed rpm also saves time by allowing engine torque to build up the truck’s speed.” Extra savings come from reduced wear on equipment. – FleetSmart.

“Most trucks obtain peak torque between 1,200 and 1,600 rpm, shifting should be done to keep engine rpm within that range. Over-revving on shifts wastes fuel.” – Paul Miner, Tri-County Truck Driver Training.

Just skip it

Skip gears if it’s possible to do so without lugging the engine. “Trucks should be shifted using the highest gear possible, as soon as possible. You may be able to skip one or two gears if you’re starting on a downhill with a heavy weight. Skipping gears also reduces the fuel burst that accompanies the middle of a downshift.” – Miner.

Kill the idle, before it gets you

The average truck idles away six hours per day at a cost of over $4,750 per year for fuel alone (estimated based on a 900 rpm idle, a Class 8 truck burns four litres of diesel per hour for 1,830 hours per year according to the Argonne National Laboratory in Washington, D.C. with fuel costs estimated at 65 cents per litre). Idling also wears out the engine three to five times faster than cruising speeds; adding maintenance costs and requiring more frequent engine rebuilds.

But there’s good news. Thirty per cent of Canadian fleets are already using auxiliary devices like direct-fired burners for cab heating – unfortunately manufacturers insist larger fleets, which would see an even bigger payoff, have been slow to commit to the technology, however. An auxiliary cab/sleeper heating unit can use up to 95 per cent less fuel versus idling for heat (just 96 cents for diesel to stay toasty during an eight-hour rest stop versus $19 for idle heating) and they allow a much quieter sleeping environment. Fuel-fired cab and engine coolant heaters are priced between $1,000 and $3,000 installed and the payback period can be less than a year, depending on use.

More savings come from driving away soon after start-up on a cold morning, rather than a prolonged idle. This heats the cab and engine faster, gets the drivetrain working and warms up the tires so they roll better, according to Ontario Ministry of Transportation (MTO) temperature tests.

Shutting down while waiting to load or unload, and during meal stops means even more money back in your pocket. For further details on how to profit by cutting idle time, see FleetSmart’s booklet Idling Gets You Nowhere.

Smooth operators

Start slow and smooth, take advantage of coasting opportunities and avoid high revs.

On the equipment side of the efficiency picture, studies show high levels of maintenance can cut emissions by half while reducing fuel, repair and vehicle replacement costs. A finely-tuned engine provides savings of up to 33 per cent on fuel, while proper air filter maintenance can save nine per cent. Optimal tire inflation and wheel alignment also have a significant effect.

Like auxiliary devices which cut the high cost of idling, a controlled maintenance program is a ‘pay me now or pay me later’ scenario, where the investment generates longer-term savings.

How to spec a heavy vehicle for efficiency and maximum profit involves wise choices on a large number of variables, and is beyond the scope of this article. But the spec’ing issue of pushing through the air efficiently presents some compelling arguments – both for and against drag-reducing aerodynamic add-ons.

At speeds above 100 km/h, aerodynamic drag becomes the largest single power requirement of a rig. Reducing the gap between the tractor and trailer from 65 to 25 inches can improve fuel economy by up to five per cent and drag-reducing add-ons can also drop fuel costs up to 15 per cent for a full roof fairing alone.

Is there a down side?

Aero add-ons do have drawbacks and can increase maintenance requirements.

Reduced airflow to the areas covered by air dams and side skirts increases transmission and drivetrain temperatures, says the TMC.

Drivers of ‘aerodynamically-clean’ tractors also need to brake more often due to decreased rolling resistance, and this results in accelerated brake wear. Aero devices can also generate heat in the trailer gap by altering the natural flow of cooling air, reducing refrigeration unit efficiency in food hauling applications. Increased vibration from the altered airflow, and corrosion around attachment points add to wear and tear on the vehicle.

In the game of beefing up efficiency, there are many issues to weigh as you consider your unique situation, whether you’re an owner-op, fleet manager or company driver. But it’s clear that slower, smoother driving combined with choices for high-efficiency equipment and maintenance can cut emissions and stress levels, while raising profit margins.

Trucking like the tortoise, might just be your fast lane to success.


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