MACON, Ga. — A school district here has grown the propane-powered portion of its fleet to one-quarter as it has reaped significant benefits from the buses, such as less maintenance, lower costs, and a lighter carbon footprint.

When Anthony Jackson accepted the post of director of transportation for the Bibb County School District (BCSD), he inherited 31 Blue Bird Vision Type C propane buses.

Although he didn’t have firsthand experience with propane, his previous research pointed to the benefits of using the fuel.

Dealing with tightening standards on diesel emissions led the district into problems related to diesel emissions reduction equipment. Operating on propane instead of diesel removes the complexity and cost of after-treatment measures, which can accelerate return on investment, according to ROUSH CleanTech and Blue Bird.

Bibb County School District’s drivers and maintenance staff also prefer the vehicles.

“Our mechanics find the buses require little maintenance,” said Marvin Middlebrooks, maintenance manager for BCSD. “Routine oil changes, which require significantly fewer quarts of oil per change and filter replacements, have shown the buses to be very mechanic-friendly.”  

The districts’ drivers discovered that the drivability of the buses was much better, and that the noise level decreased, compared to diesel.

Equipped with a ROUSH CleanTech propane fuel system, each Blue Bird Propane Vision runs on the Ford 6.8-liter V10 engine with a Ford 6R140 automatic transmission. The engine delivers 362 horsepower and 457 pounds per foot of torque, providing the performance drivers need for this urban area.

With the propane buses performing so well, the district decided to begin shifting their fleet away from diesel, adding 22 new Blue Bird Propane Vision buses to the 31 propane units already in the fleet. Now, the district’s 53 propane buses make up 25% of its total fleet.

Filling up the buses takes place at a station located on the grounds of the district’s bus garage, which has a 4,000-gallon propane tank. District employees said they prefer to fuel the propane buses, because they can avoid the spills that result from diesel fueling, as well as the odor on their clothes and hands. Plus, fueling is quick; a propane school bus fuels at 8 to 10 gallons per minute, a similar rate to diesel, according to Blue Bird and ROUSH CleanTech.

Historically, propane costs about 50% less than diesel per gallon and reduces maintenance costs, due to its clean-operating properties. BCSD currently pays $0.95 per gallon for propane versus $1.33 for diesel. Added to those fuel cost savings is the $111,000 the district expects to receive in tax credits for using the alternative fuel.

Maintenance costs are lower, too. The district’s propane buses use 7 quarts of oil per oil change, and their diesel buses need almost three times that amount. For every two oil changes performed at 5,000-mile intervals, the filters for the propane buses still cost almost 40% less than those required for diesel engines, which are changed every 10,000 miles.

Additionally, propane is a clean-burning, low carbon fuel, with less nitrogen oxide, carbon monoxide, and greenhouse gas emissions than conventional fuels.

BCSD expects to see a return on investment for the propane buses in four years, and has approved a plan to purchase more propane buses.

To read the full case study, go here.