Among the myriad topics that school bus operators discussed at the 2016 School Bus eXchange (SBX) in April were questions about fuel choices.

Roundtable participants weighed the pros and cons of diesel, gasoline, and alternative fuels. There was no clear favorite fuel, but one takeaway was that maintenance challenges with diesel emission systems are prompting many fleets to consider other fuels for their school buses.

In analyzing our most recent school bus sales data, for the 2015 sales year, we can identify some interesting trends in the fuel types.

Diesel still accounts for the lion’s share of new school buses. In the 2015 sales year, 31,262 (78%) of the total 40,190 school buses sold in the U.S. and Canada were diesel.

Meanwhile, sales of propane school buses have been steadily increasing in recent years. In 2015, there were 2,160 propane school buses sold, which was 5% of the total sales units.

The propane school bus sales in 2015 were an increase of 340 units, or 19%, compared to propane school bus sales in 2014.

More anecdotally, we’re hearing about many fleets buying more propane buses after testing out their initial purchase of them. For example, Bibb County (Ga.) School District recently added 22 new propane buses to its fleet after being pleased with the performance of its previously purchased 31 propane buses. Now, the propane units make up 25% of the district’s total school bus fleet.

Compressed natural gas (CNG) is another alternative fuel that has taken root in the school transportation industry, although sales are significantly lower than those of propane. In 2015, there were 269 CNG school buses sold, accounting for just under 1% of the total sales.

The CNG school bus sales in 2015 were a decrease of 77 units, or 22%, compared to CNG sales in 2014.

As we collected sales data from the OEMs for 2015, no sales of electric school buses were reported. However, as you’ll read in Nicole Schlosser’s June issue feature, electric school buses have only become commercially available in the past year, and there are multiple projects underway to test the viability of electric school buses and to convert older diesel buses to run on electricity.

In the roundtable discussions at SBX, one of the questions raised was whether electric buses will ever be popular in school transportation. The consensus among attendees was yes, although it may take some time.

The other fuel that appears in our sales data is gasoline. In 2015, there were 6,499 gasoline school buses sold, which was 16% of the total. Notably, gasoline accounted for a wide majority — 87% — of the Type A small school buses sold in 2015.

While gasoline is prominent in the small school bus market, there has not been a gasoline Type C or D large school bus offered by major OEMs in recent years. That is now changing.

Last year, Blue Bird revealed details on a new gasoline-powered Type C school bus, to be made available this year. Also, IC Bus has signaled its plans to offer a gasoline engine option in the near future.

Gasoline was a topic of discussion at SBX, and roundtable participants cited some potential benefits: reduced maintenance costs, a simpler engine, and a lower upfront price for the bus.

As our sales numbers show, diesel still dominates the school bus market, but there’s growing interest in the alternatives.