The drag cars are an offshoot of the kits that ROUSH Performance uses to convert gasoline-powered Ford pickups and vans to run on propane. One advantage that propane has, especially in a drag racing application, is that it has an octane rating of 106 (premium unleaded is typically around 93 octane).

The first car being developed is a 2005 ROUSH Stage 3 Mustang which will be driven by Donnie Bowles and expected to be testing in mid-November. The ROUSH engineering team is also building a 2010 ROUSH Stage 3 Mustang for Susan Roush-McClenaghan which should debut in February.

Both cars will use an all-aluminum 5.4L, V-8 Ford engine that was originally designed for the Ford GT supercar. This engine will be converted to be naturally-aspirated, the compression ratio will be altered to 12.5:1, and several other changes will be required to run on liquid propane. These include CNC ported cylinder heads, high performance camshaft and valvetrain, and a wet sump lubrication system. All these changes should help this engine generate in excess of 600 horsepower.

On average, propane fleet vehicles reduce greenhouse gas emissions by 19% and create 20% fewer nitrogen oxides, up to 60% less carbon monoxide, and fewer particulate emissions, as compared to gasoline. From an economic standpoint, propane used as a motor fuel can be purchased for about one dollar per gallon with applicable federal incentives.