What does the price at the pump actually have to do with what is being made? Artificially raising the price of fuel is a needless burden on people, and isn't going to have a huge effect on what cars are being produced.
Want a tax that will encourage efficient cars? Tax the hell out of inefficient systems, and provide rebates on efficient ones. People who are struggling to make ends meet with their current old car aren't slapped with extra taxes they can't afford. Directly impacts people who are actually buying new cars,... You know, the people actually encouraging what the automotive industry produces. The guy buying the cheapest used car he can find has zero impact on what new models hit to road, so why should he get hit with a tax designed to change what is being put on the market?
This is exactly the point I was trying to make above.
The president can give speeches and demand that the auto industry improve efficiency by 10%.
That won't even cover simple population growth. The census showed the population over the past decade were at 10.6% increase.
Assuming they want cars at the same rate as their family and friends have done, we're losing ground. Plus add more drivers, more traffic, more sprawl, and demands for the fuel will increase.
Then consider the many nations that are just now beginning to also acquire our thirst for fossil fuels, notably China.
While improving efficiency of the current problem can help it last longer, it won't fix it. It won't change until we have enough market force. In the near term the market forces will simply roll over to different fossil fuels like natural gas. It's the same problem, just at a different cost.
It won't be until the fuel is substantially higher that we'll see a change. It must be high enough that the cost difference covers the currently more expensive technology, plus covers the expense to move over.
Politicians value their seats too much to raise taxes on fuel enough to force the market to change, so we're in a situation where we simply wait for the prices to explode and the market to find a new route.