You're right because internal combustion engines are so inefficient that more than 50% of energy is wasted before it can even contribute anything. But in terms

You're right because internal combustion engines are so inefficient that more than 50% of energy is wasted before it can even contribute anything. But in terms of useful energy leaving the engine it's a different question. Once you get to long-haul speeds, the energy cost is almost entirely split between air resistance and rolling resistance, but air resistance has the edge, (about 50%), rolling (30%), drivetrain (5%), and everything else (10%).