The side-port exhaust used in the rx-8 generation RE substantially improved the emissions situation, but the fuel efficiency is still trash by modern ICE standa

The side-port exhaust used in the rx-8 generation RE substantially improved the emissions situation, but the fuel efficiency is still trash by modern ICE standards. It's been awhile since I gave a damn about wankels (or ICEs in general), but ISTR there being a relatively low limit to achievable static compression ratio due to the fundamental geometry of the swept volume. Modern ICE engines are largely exploiting the combination of direct injection and the high compression ratios it enables to improve their thermal efficiency. Between the relatively low compression ratio and sub-optimal combustion chamber shape and the fact that it migrates around the housing with the power stroke, the wankel is pretty much doomed in a world that cares about efficiency. disclaimer: I've worked hard to discard all my gearhead knowledge, but went fairly deep down the rx-7 rabbithole in my 20s-30s. Take the above with a big grain of "I may be senile and overconfident in stale once-deep knowledge" salt.