Running automobiles on household ammonia

Nobody will believe that you could do this.  Maybe you can't, but wait.  Let's take a look at a few facts and speculations.

1. Household ammonia is about 10% ammonia by weight.  If you were to use that ratio, it would take a 170 kg tank (  374 lbs ) to get 3 kgs of hydrogen out of it.  In other words, it could fit on a car. Instead of using fuel cells, let's burn it in an internal combustion engine.  The ammonia, that is, not the hydrogen.  I'm guesstimating that this will yield the energy equivalent of 3 gallons of gasoline, but I  may be wrong on that.
2. With 3 gallons of gas and at 30 miles per gallon, that would yield a range of 90 miles.
3. With a plug in hybrid with a battery range of 70 miles ( Nissan Leaf ), you could drive on the highway for an hour and a half on the ammonia alone.  Meanwhile, it is recharging the battery.  For a Nissan Leaf to have that range, it must have a battery of about 70/3= about 23 kwh capacity.   Enough to drive an hour at highway speed. 
4. If you could recharge that battery before the 90 miles is over with the ammonia run internal combustion engine, you could drive another 70 miles.  Total range could be 70+70+90 equals 230 miles.
5. If the engine was more economical, you could go further.

But how would you use household ammonia in an internal combustion engine?  You would convert it to pure ammonia before it goes into the combustion chamber.  Ammonia will come out of solution if it is heated sufficiently. You would need a heater.  The exhaust manifold on an internal combustion engine gets pretty hot.  Ammonia is a great refrigerant.  You could use that as an air conditioner and to cool the engine too.

In other words, you could make it work, but the car is starting to get complex.  It may violate the KISS principle, but it could work.

But Aronsson's Silver Volt gets much further range on his batteries, plus he has a gasoline engine ( 50 hp ) that will recharge the battery.  Just run his gasoline engine on household ammonia!  It may not be Zero Emissions, but it's getting pretty darned close.