If the US increased mileage efficiency to to 80 MPG we would probably use about a 2/3 less oil. (These are rough numbers) If China and India increased their car ownership from 1 or 2 percent to just thirty percent we'd still be in the same boat--as that would increase the car fleet by roughly 650 million. The 2/3 gain would get burned by China and India. Add in oil production declines. And what is going to happen faster? Oil depletion, China/India car growth, or American adoption of 80 MPH cars?

Electrification is the only long term way of getting around.

Certainly any oil conservation we do will be "used up" by the developing world. That is NO reason not to do it anyway. The big damage that is being done to our economy via the imbalance of payments is hurting us severely. But you are correct that electrification looks to be the obvious route to take.