On Friday, June 22, Motor Authority notes that the last rotary engine powered car, an RX-8 Spirit R, rolled off of Mazda’s assembly line in Japan. After a lifespan in production vehicles stretching some 45 years, poor fuel economy and high emissions killed what fans would argue is the smoothest engine ever built.

On paper, it’s easy to point out the advantages of a rotary engine. They’re small and lightweight, and consist of far fewer internal components than a piston engine. When properly tuned, rotary engines are exceptionally smooth and produce a surprising amount of power for their size.

On the downside, early rotary engines had problems with apex oil seals, and high oil consumption became an associated trademark of rotary power (although, by design, all rotary engines consume some oil). While theoretically simpler than piston engines, rotary engines proved difficult for some dealerships to master, leading to a hit or miss service experience. Finally, to make decent power, rotary engines need to be run to high RPMs, sucking down an impressive amount of fuel in the process.

While the Renesis (short for “Rotary Genesis”) engine introduced in the Mazda RX-8 was as step forward in engine design, the elemental problems still existed. Customers complained of poor fuel economy and high oil consumption, and even print magazines panned the car for being down on power unless revved to the sky. By 2010, all this proved to be a moot point when the Renesis engine failed to meet Euro 5 emission standards, and was dropped from Mazda’s lineup in Europe. American sales ended in 2011, although there are still plenty of RX-8s to be had from dealer inventory.

What happens next is the big question for Mazda. The rotary engine is elemental to Mazda’s history, especially in relation to sports cars. Still, the company is struggling financially at the moment, and has placed all its chips on the SkyActiv marker. Ironically, for the rotary engine to be reborn, Mazda needs its SkyActiv fuel-sipping technology to be a commercial success.

We’ve driven enough rotary-engined cars over the years to know this much: the automotive landscape is that much bleaker without a Wankel-engined sports car alternative from Mazda. We hope this is a temporary gap, not a permanent one.