Study after study shows that the most effective means of cutting fuel costs is smart driving. The dozen tips below were collected from a group of pros who know what works

Get moving shortly after cranking over the engine and shut it off as soon as you can. A modern diesel (and even most old ones) need only a few minutes to warm up, and the temperature will rise as you leave the yard. A hot engine and its turbocharger will likewise cool down adequately while heading for a yard, customer’s dock or truckstop. Except in extreme conditions, limit warm ups and cool downs to five minutes.

“Short shift.” When starting out, upshift at low RPMs in low-range gears, gradually increasing revs as road speed increases. For example, if the engine idles at 600 rpm, gently engage the clutch, let the truck start moving, then apply a little fuel. Shift to 2nd at 1,000, to 3rd at 1,100, to 4th at 1,200 and so on. (This is also called progressive shifting.) Never rev the engine to its top governed speed (especially if it’s a 2,100-rpm engine) unless you’re climbing uphill and need a bit of extra time to upshift.

Use momentum. We instinctively feather the accelerator to maintain speed but often don’t have to. Get off the accelerator way before you approach a speed zone and downshift only enough to avoid bogging down the engine. Then watch as the truck drifts for blocks with no power application. This works especially well in the wee hours when streets are deserted and traffic signals are disabled.

“Play” with traffic lights. Sure, you learned this as a teenager, but maybe you’ve forgotten it. Approach red lights slowly and try to time your arrival at the intersections just before the light turns to green. That saves you a stop and allows you to keep moving more or less steadily.

Get out of town. Studies have shown that stop signs, traffic lights and stop-and-go traffic consume fuel more than almost any other negative factor or bad habit.
Cruise in the engine’s “sweet spot.” The point where power and economy are highest is around 1,450 rpm in many of today’s heavy diesels and about 1,600 rpm in those made in the late ’90s and early ’00s. Smaller engines have sweet spots, too. Find out where they are by getting published information from engine builders, and cruise down the highway at that engine speed.

Use cruise. Many engines are set up to deliver more power and torque when cruise control is engaged, so turn it on and use it. However, CC is blind, so it doesn’t know when you’re coming up behind slower-moving traffic, or about to begin climbing a grade; in those cases, disengage cruise control and drive the truck manually.

Plan your ascents. Avoid storming a hill at the highest speed possible. Instead, estimate the final gear you’ll need to top it. Get into that gear early and stay there. Feed the engine only enough fuel to sustain that gear. Ease off the pedal as you crest the hill and upshift just before you reach the top, then stay off the footfeed and let the truck’s momentum carry you over.

Let gravity work. As you begin rolling downhill, leave the accelerator alone. Skip-shift as speed climbs, but let revs go up if you’ll need the engine brake to control your downhill speed.

Don’t overuse the engine brake. Trying to downshift too frequently to get maximum retarding power will often result in your going faster than you should. You also risk missing a gear. A combination of the engine brake and gentle applications of service brakes will be smoother and cause less wear.

Avoid idling. Even at really long red lights. (You know where they are if you’re on a regular route), Or for freight trains. Always turn off the engine when you stop and get out to use a phone booth or go in for lunch. The cab will cool off or warm up again within minutes of your return, and while it’s doing so, you can do a walk-around.