Yes that was true, vapor lock was a real big problem, when suction fuel pumps were hung on hot engine blocks, back in the days of carburettors.
A whole lot of vapor lock is eliminated by putting the fuel pump ‘in the tank’ instead of hung on the side of the hot engine, ala old US car company technology. Return loop fuel systems cure the rest because they return unused fuel to the tank, where it cools. Direct injection engines will likely take vapor lock out of the vocabulary completely.
I don’t agree with the comment. I have had leftover winter gas in an inboard engine and it worked fine when fired up in the summer. Admittedly its a single case but it didn’t blow up, and it was an old style carburetor engine. I have also driven up and down the mountains in Colorado and altitude is a problem, with power output, but not with modern fuel injection engines. Ones like Toyota uses, not like GM uses. Engineering does wonders for oldtime problems.
The pseudo-science often being pushed to further an agenda by the liberal “Oil Drum”, got to watch it over there. Peak oil is one of their biggies, which is total BS. Hello, is that your money going into that site, Mr Soros