It’s been 44 years since Mazda first launched the Cosmo with an unconventional rotary engine. In the years since, Mazda has become synonymous with rotary engines, despite the fact that piston-engine vehicles make up the lion’s share of their worldwide sales. Certainly no manufacturer has done more to develop the rotary engine than Mazda, who views the technology as an essential part of its soul.
Rotary engines have some significant advantages over their piston counterparts. They’re smaller, lighter and far less complex, which (in theory) makes them more durable and easier to work on. Because of their size and light weight, they’re ideal for use in sports cars, and they take well to forced induction for even greater levels of power.
On the down side, rotary engines are as thirsty as big V-8s, and only make serious power at the top end of the tachometer. They may be less complex, but their unconventional design means that few mechanics have much experience with them. They tend to burn oil, which is sucked into the combustion chamber to help lubricate the apex seals. Rotary engines don’t burn as clean as piston engines, and the current Mazda RX-8 was pulled from the market in the EU last year, when it was unable to meet EU emission standards.
Mazda has been working on a replacement for their Renesis engine for quite some time, but it now looks like development has been halted for both technical issues and financial ones. Mazda’s head of product planning and powertrain development, Kiyoshi Fujiwara, reports that two of three technical problems have been overcome on the new engine, but Fujiwara wouldn’t elaborate on the issues resolved or the issues remaining.
The bigger threat is a financial one: Mazda has sunk a lot of development money into the Skyactiv engine and transmission program, which aims to produce environmentally friendly cars that are still fun to drive. That leaves very little available funding for future products, especially those with modest payback potential. Of all the options open to Mazda, shelving future rotary development, at least for now, looks like the most sensible.
Source: Wards Auto