By slightly over-spec’ing engines in order to run more consistently in the “sweet spot,” choosing a gear ratio low enough to suit a fleet’s application and location, and enabling the correct fuel-efficient, engine-specific parameters, fuel economy will improve by around five percent.
PHH FirstFleet offered the following list for achieving better fuel economy:
- Increase engine torque ratings – Increase torque ratings to decrease time spent in the high output torque ranges.
- Decrease gear ratio – Choose a lower gear ratio to improve fuel economy.
- Stop Speeding – Above 70 MPH, a tractor’s engine works to overcome aerodynamic drag.
- Idling – Idling uses .5 to 1 gallon of fuel per hour.
- Progressive Shifting – Drivers shifting quickly in lower gears prevents over-revving, which decreases fuel consumption.
- Spec APUs – Auxiliary Power Units allow drivers to run peripheral applications without running the engine.
- Aerodynamics – New innovations in trailer aerodynamics decrease wind resistance.
- Lower Weight – New low weight materials allow for more potential fuel economy gains.
- Low Profile Radial or Wide Based Tires – Research indicates that fuel economy can improve as much as two percent to five percent by using low profile and/or wide based tires and wheels.
Wal-Mart used some of these same techniques to increase the fuel efficiency of its fleet by about 15 percent.