Ammonia from natural gas may be cheaper than gasoline

According to a more careful reading of that link in my post.  Natural gas prices ( 2010 in the link ) were about 1/6th the price of gasoline.  This is on a BTU cost basis.

If you were to convert natural gas to ammonia, run the ammonia in Stirling powered hybrid car, you could achieve even more savings.  Therefore, the stumbling block isn't necessarily price, it is probably going to be in the acceptance of a new way of doing things.

Stirling powered engines should be more efficient than internal combustion engines.  They were in the seventies when Ford experimented with them and found that they could save up to 30% on fuel costs.  A Stirling engine can run on any heat source, so combustion of ammonia would work just fine.

Now, if I could only get a few hundred million bucks to build a prototype, I could prove it.  Or maybe you could talk a major manufacturer like Ford to try marketing something they already experimented with.