Saving $$ on School Transportation
By: Ramses Banda

Everyone is trying to pinch pennies at the pump, and schools should be no exception. So, what actions can be taken to save some of your funds from going to the fuel pumps?

There are a number of factors both inside and beyond an engine that can increase or decrease fuel economy. It is necessary to understand how your equipment, maintenance, and driver behavior impact a bus operation. Consider the following from these categories as you look to curb fuel costs.

Here are the factors that impact fuel economy.

Driver Behavior
A bus driver's behavior is the first factor to consider when determining how to impact the fuel economy of a bus. The bus driver can have as much as a 30 percent impact on the fuel economy based on their driving techniques.

Techniques such as avoiding sudden accelerations and excessive idling can have a positive impact on fuel economy. For example, since idling yields 0.0 MPG, one hour of idling can reduce fuel economy by as much as 1 percent. An easy way to decrease idling is to include a Vehicle Idle Shutdown Timer in a bus' specifications.

Properly train your driver to ensure consistent behavior, regardless of the route or the vehicle.

Aerodynamics
When we talk about fuel economy, a common subject that comes to mind is aerodynamics. Although it can be a serious factor to consider for highway applications, the average bus will not spend a significant part of its time at speeds above 50 MPH. This means that aerodynamic performance is usually not a major contributing factor in fuel economy for school buses.

Tires
Another major item to consider is tires. Tires can contribute to fuel economy in two ways, and each one has a tradeoff. A tire that is designed for high mileage life (such as those used in buses) will not yield the best fuel economy because of their deep tread.  However, a tire that is classified as a fuel-efficient tire (such as those used in long-haul applications) will likely experience reduced tread life because of the shallow tread of the tire.

Unless your school reserves its bus for long-haul applications, fuel-efficient tires are not the appropriate choice. The normal bus duty cycle is more severe, and it has higher scrub loads that could reduce the life expectancy of the tires. It is wiser to select a bus tire that will provide longer life and keep tire replacement costs down.

Other tire tips:

* Tire inflation is important, as under-inflated tires can reduce fuel economy by at least 1 percent and over-inflated tires reduce the life of the tire.
* Broken-in tires can provide as much as 7 percent better fuel economy than new tires.
* Ribbed drive axle tires can provide 2 to 4 percent better fuel economy than lugged tires.
* Tires make the biggest difference in MPG under 50 MPH.

Lubricants
Another factor to improve fuel economy is the use of synthetic lubricant in the axle and transmission. Synthetic lubricant will not only extend the drain interval, but it will improve fuel economy by around 1.0 to 1.5 percent. Engine oils do not behave like axle lubricants, as extensive testing has demonstrated that there is no significant fuel economy difference between synthetic and mineral-based engine oils at normal operating temperatures. A synthetic engine oil is more fuel efficient at a lower ambient temperature because synthetics flow better at lower temperatures than mineral oil.

The cost of synthetics is also a factor to consider, as mineral oil costs considerably less than synthetic oil. It is also appropriate to mention that exceeding the fill level of the crankcase will create churning, which translates to a 2 percent fuel efficiency decrease.

Axle Alignment
Tire manufacturers report that fuel economy is adversely affected by improper axle alignment. When the axle is not properly aligned, the vehicle drag increases and tires also experience excessive scrub loads against the road surface. This condition will affect fuel economy by at least 0.6 percent and significantly reduces tire life tread life.

Having a properly maintained vehicle will prevent declining fuel efficiency, but there are other steps that bus owners can take to improve fuel economy.

Fuel efficiency improvement is highly dependent on proper component specifications, budgeting, and technology. Bus owners have access to expert advice from their local dealer. Dealers will review performance needs of each customer and their application to help specify the right powertrain components.

Engine
Selecting a fuel efficient engine is the first step. New engines can provide up to a double-digit improvement in fuel savings over pre-2007 emission compliant engines, and this alone is a tangible savings in fuel costs.

Automatic Transmission
Using the fuel economy mode on the automatic transmission can save between 3 and 5 percent. This feature is usually available when you are building the specifications of the bus.

Rear Axle Ratio
The rear axle ratio can be specified to save fuel thanks to the introduction of several new technologies. Today's advanced powertrains boast improved torque delivery, which allows for a lower numeric rear axle ratio. This lower ratio maintains vehicle response while improving fuel economy.

Customers should talk with their dealer about the rear axle ratio when buying a new bus instead of simply ordering what they're used to. Otherwise, you might miss an important means of saving fuel.

Hybrid Electric Systems
The grand finale of the fuel-efficient list must include hybrid electric vehicles (HEV). A hybrid bus will provide substantial fuel savings over a similarly specified non-hybrid bus and will also increase the life of other components, such as brakes and tires.

The anticipated fuel-efficiency improvement ranges from 20 percent to more than 70 percent, depending on the selected technology (non-plug-in or plug-in), the route, and driver behavior. Since the HEV system uses regenerative braking, brake pads are used less often, with resulting benefits for both tires and brakes. A local dealer can highlight all of the benefits of a hybrid bus and evaluate which technology is the best fit for your school.

Your school buses may currently be guzzling fuel, but you should now be well-equipped to save money at the pump. Properly maintain your vehicle, train your driver, pay attention to specs, and explore new technology, such as a hybrid bus, that can drastically improve fuel efficiency. Happy trails, and enjoy the savings.

Ramses Banda is the bus platform marketing manager for IC Bus, headquartered in Warrenville, Illinois, and an affiliate of Navistar, Inc. The company is a leading producer of commercial buses for several markets, www.icbus.com.