• Improving fuel mileage from a personnel standpoint begins with effective driver training.
• Drivers must be trained on shifting, speed, idling, and fueling for the most effective outcome.

Driver habits and performance can be one of the largest factors in fuel mileage, influencing fuel mileage as much as a mile per gallon. Training must impart correct driving techniques to the drivers and emphasize the importance of using them, including:

• Progressive shifting,
• Low revolutions per minute (RPM) driving,
• Operating at a slightly slower speed,
• Maintaining steady speeds, and
• Idle reduction.

Progressive shifting and low RPM driving

Training drivers on progressive shifting and low RPM driving is typically a safety/training department function. However, by downloading engine data at the time of service, the maintenance manager may become involved in the process. High RPM spikes and high average RPMs are typical of a driver not using progressive shifting or constantly operating at high RPMs.

Typically, these drivers believe that to get the engine to perform correctly the engine must be kept at high RPMs, and that maintaining high RPMs will reduce the number of shifts that are necessary. Both of these points are false. As a maintenance manager knows, it’s actually torque, not high RPMs, that makes an engine perform well. Keeping the vehicle at high RPMs keeps it above the peak performance areas. Also, if the driver is downshifting at high RPMs, the driver is never giving the engine a chance to pull (downshifting before even getting into the engine’s peak torque range).

Finally, there are software programs that can be installed on engine computers that limit the RPMs at various road speeds. These programs force drivers into using progressive shifting. This should be considered if the majority of the fleet has a problem with not using progressive shifting.

Slower speeds

Some drivers might believe that a vehicle can be equipped to operate efficiently at any speed if the driveline is correctly configured. These drivers must understand that speed equals air resistance. No matter how efficient the driveline is, air resistance cannot be avoided. Fuel mileage drops as much as 5 to 8 percent for every 5 miles per hour over 55 miles per hour (depending on vehicle configuration), no matter how well it is geared. Graphing the air resistance can many times demonstrate the issue to the drivers.

Here again, the people who train drivers are normally in the safety or training group. However, the maintenance manager can lend the training person expertise and facts in this area.

By reducing the speed at which the vehicles are operating, the company can realize a considerable fuel mileage improvement. This will normally generate a considerable push-back from the drivers (and possibly increase driver turnover), as reducing the speed at which the vehicles operate will reduce their income.

As well as limiting speed, the power of the engine can also be adjusted in many cases. Be aware, reducing the power the engine can generate may have the same effect on driver performance as reducing the vehicle speed, and may cause the same problems.

Maintaining steady speeds

A maintenance manager can notice certain driving behaviors when downloading the vehicle computers, and when performing maintenance, that indicate a driver is not maintaining steady speeds. Common indications are a high number of hard-brake incidents on the vehicle computer and excessive brake wear on the vehicle.

What is typically causing this (high number of hard braking incidents and excessive brake wear) is the driver having to make radical speed changes due to not finding a good cruising speed and “running with traffic.” This driving habit causes a reduction in fuel mileage, while also being potentially dangerous. A carrier’s maintenance manager may not be directly training drivers on good defensive driving techniques, but the information generated by a maintenance department can be critical to the people that do.