True, turbos (even dual compressors as in the case of VAG's TSI) have much impact, but even non-compressed engines (in lower end models) are vastly better-behaved than old car engines.

I once had a Sunbeam Avenger which was horrible in very many ways (not least because of the build quality in English unionized car plants) and an uneven torque curve (with a peak and a not that high peak as such) was one of its problems.

Newest cars are only lighter when compared to recent history. Cars of 1960's were much much lighter than today.

(big-family-sized Cortina DeLuxe of 1962 was 787 kg, present-day supermini Fiesta starts at 1041 kg).

The 1.25 Studio is so slow that it isn't available for sale in the USA--the cheapest $14k model here does 0-60mph in 9 seconds or so.

This may depend on geographical area and standards and so on, but at least here in northern Europe, much of the gasoline was made of Russian crude oil and before modern emission standards, it contained lots of sulphur and other impurities. I believe modern cars would start flagging errors with even 1980's gasoline (again, even assuming that the lead would be taken away and replaced by modern additives).