I have to agree. The highest specific output DI engine that runs regular gas is probably the GM 3.6 with DI. In a performance tune, only available in certain models, it produces as much as 89 HP per liter. Even if a direct injected 3.0L flat six from Subaru could match that output, which isn't likely, we'd still only be looking at maybe 270 from a 3.0L displacement.What are you gonna believe ...reading or physics?
100 hp per liter would require nearly 88 lb-ft per liter at 6000 rpm,
(that would correspond to peak torque well over 95 lb-ft per liter).
Mazda's 2.0 DI engine generates peak torque of only 75 lb-ft/liter,
and less than 68 lb-ft per liter @ 6000 rpm (peak hp). Their 2.5L
direct injection engine has nearly identical figures.
Please identify JUST ONE naturally aspirated production automotive
engine that generates 100 hp/liter @ sane rpm -- on 87 octane fuel!