This is just like trying to replace a pressure washer with a 5 gallon bucket. Just because both can supply 5gpm to the work surface does not mean that the bucket is gonna cut the paint off the concrete. There's a little matter of pressure + volume to deal with here. So a bilge blower can deliver 250cfm. What psi is that delivered at? A couple of inches of water column? It takes over 30' of water column for leas level air pressure of 14.7psi. You would get better results by putting 5psi in the tires.

And Frank, none of those suggestions is green enough. You need a cage full of cute little bunnies in the back, feeding the methane to roof mounted subsonic ramjet. You can just sweep up the cages and put it back in the feeder hoppers, as it apparently undergoes no alimentary change in the wabbits. This will need some wind tunnel modelling like a scramjet to get reliable combustion and effective thrust, but we can leave that to the wind tunnel boys up at Tullahoma. The only remaining input is water, as the bunnies are self replicating.

This system will discourage tailgating, reducing accidents and thus insurance costs, and in the event of taking a wrong turn in the blizzard because you bought cheap gps, you have survival rations plus something warm a cuddly.