alt Hacker News>Turbos no longer mean you have to sacrifice fuel economy for performance (unless you have a lead foot).
That's incorrect. Virtually every turbo'd gas car runs slightly richer than stoich to use the unburnt fuel to manage temp/knock. Diesels, you actually get more efficiency out of with a turbo for free. With gas you're practically guaranteed to be throwing fuel out the pipe.
That isn't some turbo specialty, the effect is the same in both NA and turbo engines. And AFAIK it isn't really feasible anymore. I don't know about other manufacturers, but for example Volkswagen Group's EA211 EVO2 engines run pinned at lambda 1 no matter what.