Eastern Carver County has found them to be cleaner and cheaper than diesel-fueled ones.
On his first day behind the wheel of a new kind of school bus, Keith Muirhead made a surprising discovery.
The propane-powered bus had more giddyap than the diesel buses he usually drives.
"It's like getting out of my pickup and getting into my Corvette," he said Thursday after dropping off students from Chaska High School in Minneapolis for a field trip.
All this week, Eastern Carver County school drivers have been testing the propane bus -- said to be cleaner, quieter, more powerful and cheaper to run than other gasoline and diesel-powered models -- to see how it performs in the dead of a Minnesota winter.
Should it pass the test, starting up every morning and running well all day, district leaders say they'll likely make the switch this spring with most of their buses when their new busing contract goes out to bid.
That would make Eastern Carver County Schools the first Minnesota district to convert from diesel to propane-fueled buses, and it could pave the way for other districts to follow suit.
The St. Francis School District has already ordered a smaller school bus that runs on propane for transporting special education students, and it's set to arrive as early as next month.
Other Minnesota school districts eagerly waiting to try out the new bus include Minneapolis, Bloomington, Waconia and Pequot Lakes.
California and Texas school districts have been using propane buses for years as a way to satisfy those states' stringent emissions requirements.
But in Minnesota, the weather, as always, is a concern. Propane must overcome some stigma among Minnesota bus drivers who remember when some school buses ran on propane in the 1970s and '80s, and often stalled in frigid weather.
Now, the newer buses, manufactured by Blue Bird, seem to have conquered the problems with cold with improved technology.
"It started right away. It heats up beautifully," said John Thomas, transportation coordinator for Eastern Carver County Schools. "Right now, I'm pretty confident we'll be asking for these."
Not only is the propane fuel cleaner than diesel, he said, but it's also cheaper.
The chance to save money on transportation costs, one of the biggest expenses for many school districts, is especially appealing at a time when school districts are struggling with budget issues.
Propane runs between $1.50 and $1.75 a gallon currently, compared with diesel fuel at $2.85 a gallon, and a federal tax refund is available to further offset the cost of the fuel purchase.
Those savings could be passed on to the school district, Thomas said.
The Eastern Carver County district doesn't own the school buses that carry its students; it contracts out with Positive Connections, a private company. The district uses about 120 school buses a day and says it could seek to replace as many as 85 of those buses with propane models by next school year.
Maintenance costs would be less with the propane buses, too. Buses that run on diesel need an oil change about every 3,000 miles. Those fueled by propane can go 10,000 miles before they would need an oil change, Thomas said.
Last year, the district's buses averaged 17,000 miles each; its fleet made the equivalent of more than 80 trips around the globe, district officials said.
Estimated cost savings for the district should it use an entire fleet of propane school buses would be between $100,000 and $120,000 a year.
Still, the move to the new buses would be more expensive on the front end, Thomas said.
That's because the company would need to spend about $15,000 on top of the actual purchase of each school bus in order to convert it so that it could run using liquid propane.
"This is new technology, so you'd think down the road, as it becomes more popular, that $15,000 is going to shrink," Thomas said.
More tests up north
Mid-January seemed an ideal time to find out if the new bus could withstand the harsh windchills and low temperatures typical this time of year.
But the milder weather this week has left the question of cold weather performance somewhat unresolved, district officials acknowledge.
"We would have loved to see it two weeks ago when the temperatures were below zero," Thomas said.
They may still get their chance.
After the bus leaves the Chaska area, it's scheduled to head north to Pequot Lakes and a few other school districts in northern Minnesota, where it will more than likely encounter subzero mornings. Thomas said he plans to call his transportation counterparts in those school districts to find out how the propane bus performed.
Cold weather was an issue with biodiesel-powered buses last year in some metro area school districts. Bloomington schools closed for a day last January after biodiesel fuel gelled in about a dozen school buses once the temperatures dipped below zero. Some students were left stranded at their bus stop or sitting on stalled buses.
Allie Shah • 612-673-4488