So, with the help of the S.11 Vehicle Energy Conservation Study Group of  The Maintenance Council (TMC) of the American Trucking Associations, we’re going to look at some of the ways you can conserve fuel – and where the real fuel economy is.  We were impressed with the Study Group’s results, and we think you will be too.

It depends on what you mean by “best.” Some fuel economy measures require equipment purchases, some equipment modifications, and others changes to the way you operate your fleet.

WHICH METHOD COSTS LEAST?

Again, you’ll have to be the judge. Changing the way you operate may not cost anything in terms of equipment or component purchases, but it may require a considerable investment in employee education.

And if you decide to invest in a driver fuel economy incentive or bonus program, that will certainly cost something, and you’ll have to balance that cost against the benefit of the fuel you save.

WHERE SHOULD WE START?

Let’s look at some of the things we know. The chart on this page, called a “fishbone” chart, shows some of the factors that affect fuel economy in the real world. We’ve divided them into 6 large categories: Tires, Drivers, Vehicle, Documentation, Environ ment, Operations.

WHY DOCUMENTATION?

Documentation is critical. If you don’t know what fuel economy you’re getting now, you won’t be able to tell whether the fuel economy methods you try are working or not. And, you certainly won’t be able to determine if it was a good investment.

You must get a handle on your current fuel economy performance before you can decide whether a change is for the better.

WHAT DID THE STUDY GROUP FIND?

TMC examined more than 60 different factors, drawing on member experience as reported in Task Force meetings. Here are the results, based on:

• Class 8 tractors
• Coupled to 48-53 foot trailers
• Maximum gross weights of 80,000 lbs.
• Dry or refrigerated van applications
• Maximum vehicle speeds of 65-70 mph

Editors Note:  The information reported is taken from Recommended Practice 1111 of  The Maintenance Council of the American Trucking Associations, used with permission.  Because there are so many factors involved, and because individual results may vary, these numbers should be considered guidelines only.   You should test thoroughly before adopting any of these fuel economy techniques fleetwide.

Factors Affecting Fuel Economy in the Real World

(Numbers in far left column are for reference to other charts)

If we apply the Willie Sutton rule, it makes sense to look at those things that have the biggest effect.

We calculated the average MPG improvement (because that’s more likely than the maximum or the minimum), then ranked the methods in order of size of the effect. Here are the top ten:

Top Ten Fuel Economy Factors

Of course not, but these results do suggest that if you have different operations within your fleet, you’re going to need different fuel economy goals for each of them.

And, if we eliminate routes, loads and weather, some interesting things happen:

Notice that the “Best Drivers” came to the top of the list, and that four out of the top ten factors, including speed and idling, are under direct control of drivers.

Top Ten Controllable Fuel Economy Factors

It certainly does. With 35 percent or more of your fuel efficiency in your drivers’ hands (or perhaps we should say "under their feet"), a program of fuel economy education – and possibly fuel efficiency incentives – could clearly reap big rewards.

HOW BIG?

If a power unit logs 100,000 miles a year, using diesel at $1.15 a gallon and normally achieves 5.5 MPG, the fuel cost for that vehicle is about $20,909 per year.

And if your drivers could improve their MPG by 17.5 percent (about half the maximum reported by the Study Group), MPG would go up to nearly 6.5, and fuel cost would drop to about $17,795 per year. That’s a savings of over $3,000 per year per tractor – or about 3 cents a mile.

WHAT IF WE TRY ALL THESE THINGS?

Well, first of all, you really can’t do everything. There are over 60 different factors on the TMC list, and there probably are many more that weren’t even investigated. But if you could implement the top 10 you could improve your MPG considerably. And W illie Sutton would be proud of you.

The American Trucking Associations,
2200 Mill Road, Alexandria, VA 22314,
(703) 838-1763.

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