2 of the 3 biggest advances in power in automotive engines today compared to those of the mid 20th century are efficiency changes. Fuel injection has gotten better, whether compared to earlier fuel injection or to carburetors. It can atomize fuel into smaller, more uniform particles and disperse them with more precision during the proper part of the cycle. Stronger, lighter materials and lubricants with less friction have become standard, losing less power to parasitic power loss, and the third thing is less efficiency related, but tighter tolerances, more precise control of fuel delivery and valve timing, and stronger materials have led to the compression ratio of a regular passenger vehicle today exceeding that of performance cars back in the previous century, while staying on the same grade of fuel.