Alliance AutoGas has developed a bi-fuel propane-gasoline system for the Ford Transit’s 3.7-liter V-6 engine. The kit is called “plug and play” because the propane components easily bolt and plug in, with no cutting, drilling or wire-splicing required.

The conversion allows the Ford engine to burn gasoline or cheaper propane, and a combined storage capacity of 46 gallons means the operator has no “range anxiety,” said Ed Hoffman, president of Blossman Services, an AAG affiliate.

The system costs about $6,400 installed, and 50 upfitters are qualified to retrofit it onto existing Transits. Installation at an upfitting center near Ford’s Kansas City, Mo., plant is being negotiated.

For now the system only works on naturally aspirated V-6s, not turbocharged EcoBoost engines, he said.

A standard kit includes a 21-gallon donut-shaped propane tank which replaces the van’s spare tire in an inverted well behind the rear axle. The tank will be crash-tested to ensure integrity in case of a rear-end collision. An optional 38-gallon propane tank would mount inside the body. The Transit’s standard 25-gallon gasoline tank is retained.

The system can change from one fuel to the other with a manual switch, or controls can be set to burn propane as long as there’s enough on board, then change automatically to gasoline, Hoffman said.

The conversion has been EPA certified and California Air Resources Board certification is being sought, he said.

The system is warranted for 5 years or 100,000 miles, and the full Ford warranty is retained. Hoffman hopes to sign Ford dealers to install the system, and plans to train them and fleet mechanics on installation.