Posted Friday, July 4, 2025 at 10:46pm
Subaru is conservative these days. It sticks with technologies it knows well, evolving its cars gradually over the years. Even when it does something new, it’s often long after the rest of the industry. But in the 1990s, Subaru was gloriously weird and experimental. Witness Subaru’s largely forgotten sequentially twin-turbocharged flat-four.
To the best of my knowledge, this is the only twin-turbo gas-powered four-cylinder automotive engine. Some automakers have done twin-turbo four-cylinder diesels, and before you jump down my throat about it, BMW’s “Twin-Power Turbo” engines use a single twin-scroll turbocharger. Not two turbochargers. So, Subaru stands alone here.
