Mazda officially retired the beloved Mazda RX-8 in 2012 due to several factors, including soaring fuel prices and more stringent emissions regulations. The inherent drawbacks of the rotary engine, such as subpar fuel efficiency, high emissions, and insufficient low RPM performance, rendered their Renesis engine outdated compared to contemporary alternatives. Since then, whispers among rotary engine enthusiasts suggest that Mazda might be quietly working on a new rotary engine to power the upcoming RX-series sports car.
However, it’s important to note that evidence supporting these optimistic claims is limited.
So, what do we know that lends some credibility to the prospect of a Mazda RX-9? For starters, Mazda aims to incorporate HCCI technology into their SkyActiv gasoline engines, as reported by Nikkei. HCCI, or Homogeneous Charge Compression Ignition, allows for higher compression ratios in engines, thereby enhancing fuel efficiency and power output by igniting fuel through compression rather than a spark plug. This innovation could elevate Mazda’s average fuel economy figures above CAFE standards, enabling the potential development and release of vehicles, such as their RX-series sports cars, that don’t need to comply with these regulations.
The second significant update, though nearly a year old, is still noteworthy. Autoblog reported on Mazda’s patent application for a redesigned rotary engine that features a compact architecture. This new design incorporates a valve over the exhaust port that can open and close at various RPMs, aimed at enhancing exhaust flow throughout the engine’s rev range. Known as the 16X, this concept also introduces port fuel injection, a departure from previous rotary engines.
The most recent news regarding Mazda’s rotary engines comes from another patent application. As noted on the US Patent and Trademark Office’s website, this patent introduces a stop-start function that seals the engine’s intake ports with its rotors. This system is designed to fire the spark plug after the fuel is cut off during shutdown, likely to expel exhaust gases rather than unburned fuel, thereby preventing flooding. This innovation aims to reduce the unnecessary idling typical of internal combustion engines, leading to better fuel economy and lower emissions.
While none of these advancements alone signals the imminent arrival of an RX-9, they indicate that Mazda has not entirely abandoned the idea of producing another rotary-powered vehicle. Perhaps, in light of the increasing competition within the sports car market, we can hope that Mazda will reignite their passion for rotary engines.
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