Also, metallurgy has improved greatly over the last 50 years or so. This allows engines to be built from better stuff, which can be machined to closer tolerances. Back in the 60s, you expected to do a top end rebuild inside of 100k miles. Now we frequently see engines go 250-300k or more without any major maintenance. Computer aided design allows better modeling of fluid flows. Lots of electronics inc cars these days, controlling every aspect of the vehicle. They will even tell you what's wrong with the car, something the 60s mechanic could only dream about.