We tried to have a peak oil in the 70's and 80's and we got improved catalytic cracking processes (google zeolites), and I believe we also got sideways drilling and (someone with a better memory, help?) ground penetrating radar during that era.
So we located more oil, we could get more of it out of the ground, and more of it made it to your gas tank.
Since then people have made the zeolites many times larger in diameter. I've no idea why that improves efficiency but that's the claim.
However through all of this the amount of energy to refine one gallon of petroleum has gone up and up. That's one of the complaints about tar sands. For some of those the yield is a 10:1 ratio (one gallon to produce 10), whereas we used to be many multiples of that ratio.
