After more than 40 years of using propane as a motor fuel, the people at The Schwan Food Co. still believe they’ve got the right stuff. Schwan’s experience with propane goes back to the 1970s, when Arab oil embargoes threatened supplies of gasoline and diesel and drove up their prices.

Schwan’s Ford E-450s are among the many that run on propane, which the company has used since the 1970s.

Schwan’s Ford E-450s are among the many that run on propane, which the company has used since the 1970s.

“The embargo was a big driver of a conversion to propane” from gasoline, according to Jeff Schueller, director of fleet maintenance, quoting a bit of company history that occurred before his time.

Reliable supplies and cheap, steady prices continue to verify that long-ago decision.

Propane is also known as LPG, for liquefied petroleum gas, because it’s a byproduct of petroleum refining. Propane also occurs in “wet” natural gas as it’s extracted from the ground, and a large majority of propane fuel is now made from natural gas.

It’s called “autogas” overseas, where it’s far more popular as an automotive fuel.

Schwan’s Home Service, the company’s home-delivery business, carries ice cream and prepared foods with 3,300 propane-powered units nationwide, a mixture of General Motors, Ford E-450s and Isuzu NPR Gas trucks. (It also has 1,300 diesels bought after GM got out of the medium-duty business in 2009.)

“We can hedge fuel purchasing,” locking in prices for months at a time, Schueller says in listing propane’s benefits.

“It burns cleaner than other fossil fuels, so we have been able to extend oil drains, and that has offered a price reduction in our maintenance plan.”

Oil analysis has shown the safety of 15,000- to 24,000-mile intervals, versus 4,000 to 7,000 miles with gasoline, which alone saves Schwan Food $1.2 million annually.

“Engines last 150,000 to 200,000 miles before they get tired,” and then are pulled and replaced with GM remanufactured long blocks,” he says.

A typical truck chassis runs 24,000 miles a year and goes through two engines before it is retired after six to eight years. Its multi-compartment refrigerated body is transferred to a new chassis, serves through another cycle, and then is scrapped.    

Fuel cost itself is significantly less per gallon after a 50-cent-a-gallon federal tax credit, compared to an average of $3.70 per gallon for gasoline. State grants are available to cover a percentage of the equipment conversion costs, which are pegged at $16,000 per unit.

“We have bulk storage tanks on our depot properties,” he explains. “We have it trucked in and refill the units each night on our properties.”

Schwan is so dedicated to propane that it has its own equipment supplier, Bi-Phase Technologies, which makes a system that replaces factory gasoline fuel injection. That system will soon be available to other users.

“We continuously look at other alternatives, other fuels, and at hybrid options,” Schueller says.

“But propane always comes back through analysis as the favorite choice.”

Propane trucks and engines

Schwan Food, an early adopter of propane, uses a propane conversion system designed and manufactured by a subsidiary, Bi-Phase Technologies.

It’s installed on trucks purchased primarily from General Motors in the past. Since GM’s exit from the medium-duty market, Schwan has been buying Ford and Isuzu trucks. Isuzu NPR Gas models come with the familiar GM Vortec 6000 gasoline V-8, which then gets the Bi-Phase conversion.

Bi-Phase has struck an agreement with Power Solutions International, a maker of alternative-fuel engines based on GM cylinder blocks, to market Bi-Phase’s propane system for general use. The system will use Bi-Phase mechanical components with PSI electronic controls.

Freightliner Custom Chassis Corp. has begun building its S2G Class 7 chassis with an 8-liter V-8 that runs on propane autogas. The S2G uses an FCCC chassis with a cab and hood from Freightliner’s M2-106.

Several aftermarket suppliers offer propane conversion kits for Ford and GM vehicles and engines. They include:

• American Alternative Fuel ( Has bi-fuel (gasoline and propane) kits for Ford trucks and cars. The company also makes CNG equipment and small electric vehicles.
• CleanFuel USA ( Dedicated propane kits for GM vehicles. It says its fuel system is used in the Freightliner S2G truck.
• ICOM North America ( Its JDG injection system is used by CleanFuel, and a bi-fuel version is available for GM and Ford vehicles and engines. ICOM also makes propane tanks.
• Impco Automotive ( Makes bi-fuel and dedicated systems for Ford and GM vehicles and engines. Impco also makes CNG systems for compressed natural gas, and assembles GM’s bi-fuel (gasoline-CNG) 2500-series pickup.
• Roush CleanTech ( Specializes in dedicated propane conversions for Ford F-series trucks and E-series trucks and buses.
For more propane options, go to The site is maintained by the Propane Education & Research Council, which works to boost the use of “autogas” in North America.