Roush F-150: Pickups Go Propane

October 13, 2008
What if you could drive a car powered by a waste product of the refining process that creates gasoline and natural gas? Great, because Detroit's Roush Industries can make it happen. The magic fuel is liquid propane, and it can power almost any 2008 Ford F-150 with a 5.4-liter Triton V-8--while it gives Hank Hill types a total adrenaline rush. Roush loaned us a converted Super Crew XLT for a few days, and we came away impressed with how normally the truck ran.

How it goes natural
Roush's offering matches the significant capabilities of the gasoline-fired F-Series when it comes to crankshaft horsepower as well as payload and towing. The conversion's focus is the fuel system, and it begins with storage; Roush offers two fuel tank sizes, a bagel-shaped Toroidal 25-gallon holding cell that occupies the same location as the truck's discarded gasoline tank, and a larger 59-gallon drum type that fits in the bed. According to Roush, most customers go for larger tank because of its 500-mile-plus range.

Forward of the tank, Roush replaces everything fuel-related, including billet fuel rails that carries the propane in liquid state to custom injectors. To take advantage of propane's higher octane equivalency (99-112 octane R/M depending on the refiner), Roush engineers reprogrammed the F-150's engine control module. The resulting output matches the gasoline-fired F-150 at 300 horsepower and 365 pound-feet of torque.

Driving the greener F-150
Sitting inside the Roush-modified F-150, there's nothing to tip you off that you driving a propane-powered truck. In almost every respect, it drives like its gas-burning counterpart, except in how it starts. When you key the ignition, except for the gauges and radio coming to life, nothing happens. If it's cold out, the fuel system takes up to 10 seconds to pressurize itself. Then, once it's darn good and ready, the starter motor magically engages and the truck fires. (On warmer days, or after when the engine is at operating temperature, the starting sequence requires less than three seconds.)

The truck quickly settles into an idle that's just a smooth as a standard 5.4-liter Ford V-8. It sounds the same, too. More importantly, the motor didn't exhibit any cold-blooded characteristics, and could be driven away from the curb as quickly as you could move the column shift into "D."

On the road, initial concerns about carrying 59 gallons of fuel above the axles quickly evaporated. The Super Crew is designed to carry more than 1,700 pounds of payload, so a full 59-gallon, 250-pound load of LP doesn't begin to stress out the Ford. Throttle response proved to be spot on and every bit the match of the gas-powered counterpart.

Since Roush changed nothing else in the truck, our rear-wheel-drive Super Crew performed exactly like a gas-powered 2008 F-150 in all other respects: ride quality, quietness, etc. Ford is on the cusp of introducing its all-new 2009 F-150, and it is clear to us that the 2008 F-150 is getting a bit old in terms of handling dynamics and ride refinement. At this time, Roush has not announced a conversion for 2009 F-150s, which will be an all-new model.

Regarding fuel economy, the F-150 runs about 10 percent fewer mpg of LP than gasoline. This loss is more than made up for the lower cost of the LP fuel, which usually tracks about 75 percent of the cost of gasoline. The net is that an LP F-150 costs less to run per mile than its gasoline-swilling counterpart.

Is propane ready for the road?
According to the U.S. Census circa 2000, almost 7 million American homes use propane as their primary fuel. The Department of Energy estimates that there are 250,000 vehicles on U.S. road powered by the fuel and close to a million worldwide (the fuel was particularly popular in Australia through the 1970s and '80s). Among LP's many benefits, propane refills take about the same time as a stop at a gas station, as the liquids flow at about the same rate. Additionally, propane vaporizes at normal atmospheric conditions, so fuel spills are literally impossible (the fuel immediately evaporates).

Chemical analysis reveals that LP is a cleaner fuel than gasoline. When burned, propane emits 40 percent less particulate matter, half the NOx, and 87 percent fewer total hydrocarbons.

Roush's Liquid Propane conversion certainly performs like a "real" truck and presents drivers with few compromises compared to a traditional gas-fired F-150. The high cost of the conversion (all-inclusive retrofit, $10,500) is daunting to an average consumer, but significant federal tax credits and the lower cost of LP (compared to gasoline) create a scenario that the added cost will be saved after several years of ownership. Municipal and commercial fleets that rack up high annual mileage figures are the truck's target market, but the push to run vehicles on something other than gasoline is likely to entice private citizens to consider propane in the coming years.

This one option won't save our country from the scourge of foreign-sourced oil, but it does demonstrate that alternative fuels can provide the same level of performance from a familiar platform while delivering a greater level of efficiency.

We have only one suggestion: Perhaps the shift lever could be a spatula.

More information is available at

Roush Ford F-150 LP Natural Gas truck

Roush Ford F-150 LP Natural Gas truck

Enlarge Photo

Roush Ford F-150 LP Natural Gas truck

Roush Ford F-150 LP Natural Gas truck

Enlarge Photo
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