Any significant increase in forecasted supply spikes the markets down the way a decrease in supply (the fear that oil platforms would be damaged in Katrina ;i.e.) spikes the markets up. The second thing it would do is signal the world that the US was once again serious about exploring every available source of energy, again signaling the markets that supplies in the future could be greater. The same thing would happen if we were to announce plans for multiple nuclear plants. Right now we have told the world, we have it, but we'd rather pay more for it from other places then go get it ourselves. So of course their yielding to our wishes and charging us more.
I don't see how this will make any significant long or even medium term difference factoring in population/economic increases in China, India etc. Plus, it's not going to be sold to the US exclusively.

Properly inflated tires do help with mileage, but 10% reduction in overall fuel consumption? Highly doubtful.