The trucking industry has paid a lot of attention to fuel economy. For them, their bread and butter depends on it. In fact, for them the word "performance" doesn't bring to mind high speeds or fast accelerations but rather good fuel economy per ton of cargo moved. Therefore looking at what they do to save on gas lets you take advantage of decades of tried and true tips and strategies. Caterpillar has published a report on Understanding Tractor-Trailer Performance which lays out the best ways they know to save gas with a big rig.
Their list of most significant factors affecting fuel economy includes these:
- Route Selection
- Vehicle Speed
- Frontal Area of vehicle
- Aerodynamics of vehicle
- Hill Grade
- Idle Time
Caterpillar is very clear that the most important factor is the driver. The driver has direct control over many things including speed, accleration rate, usage of the brakes, shifting technique and time spent stopped with the engine idling. According to the report, fleets of identical trucks reveal fuel efficiency differences of 25% between the best and worst drivers. And even a bad trucker will probably drive more fuel efficiently than the average car driver. Truckers naturally develop a hypermiling culture amongst themselves due to the economic pressures in their industry.
The second factor they discuss is route selection. Caterpillar notes that driving in heavy traffic on congested roads notably increases fuel consumption. They find that a route of which 25% of the distance is congested leads to a 15% increase in fuel consumption. A route of which 15% is congested increases fuel consumption 8%. Roughly extrapolating to other percentages of congestion will allow you to estimate the mileage penalty of congested routes. In turn this lets you trade off the fuel penalties of distance and congestion. Choosing a longer route that avoids traffic could actually use less gas.
So Caterpillar is telling us that the most important factors determining your fuel usage and fuel economy are how you drive and where you drive. Read over the report if you have a few spare minutes. If it helps you save on gas, it will be time well spent!