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Mazda patents show rotary engine for range-extended EV

Two years ago, Mazda introduced a fascinating range-extended electric car called the Mazda2 RE Range-Extender. It took an electric Mazda2, and dropped in an itty-bitty 330cc rotary engine. It wasn't the rotary-powered sports car we had hoped for, but it seemed like a unique way to keep the quirky engine alive and kicking. But not long after the car's reveal, it seemed to disappear. Now the basic idea has resurfaced with a few modern updates in a couple of US patents. The first patent is pretty straightforward and describes a range-extended EV similar to the BMW i3. At the front is an electric motor driving the front wheels. At the back is an internal combustion engine that powers an electric generator. In the middle is a lithium-ion battery for storing and delivering electricity. It's the same set-up as that Mazda2. The second patent is for an engine start-and-stop system, but specifically for rotary engines. The system is designed to shut off a rotary engine when not needed, much as modern piston engines do. It also stops the rotor in a position that closes the intake port to ensure no fuel or exhaust emissions slip out through the intake tract. This is necessary since there are no valves in a rotary, and air and exhaust come through ports that are "opened" and "closed" by the rotor itself. The patent also describes the possibility of firing a spark plug after the fuel has been cut to eliminate any leftover fuel emissions. This system would theoretically improve a rotary engine's fuel economy and emissions significantly, which would be a boon as those are two of the rotary's major weaknesses. The rotary-engine patent also includes the same range-extended powertrain drawing as the first patent. It's there as a description of a possible application. And in such an application, where the rotary wouldn't have to run all the time, the system could take advantage of the rotary's inherent strengths. Weight can be kept low thanks to the engine's small dimensions, which should help in keeping the car sprightly and efficient. Rotaries are renowned for smoothness, too, so it shouldn't need too much refining and sound deadening, the latter of which adds more weight. The small size would also help with packaging, leaving more space for people, cargo, or possibly batteries. And since it has been patented, the company may be looking to bring the system to market.

Mazda6 diesel engine delayed over low performance, still coming

Oh Mazda... we had many hopes for the promised diesel four-cylinder in the Mazda6, but those have remained largely unfulfilled, as the oil-burning powerplant has failed to appear on dealer lots following its 2012 LA Auto Show announcement. Despite engineering issues that forced the company to announce that the program was delayed back in September 2013, Mazda remains adamant that the 2.2-liter Skyactiv-D is still coming to our shores. "We're still very much committed to diesel," Mazda's North American CEO, Jim O'Sullivan, told Automotive News. "We are still working on getting the performance aspects up to where we want them, and we do have a plan – an engineering road map – to get it done." According to AN, Mazda's initial plan with the 2.2-liter diesel was to build an engine so clean it could get by without an aftertreatment system, which generally accounts for the price premium of diesel engines versus their gas counterparts. The new system has come with performance issues, though, necessitating the delays. "If [we were] a commodity brand and didn't care about that, it would be on the market right now," O'Sullivan told AN. "But I know the people were expecting something from us, expecting certain drive characteristics and performance, and I didn't want to disappoint them." While O'Sullivan's defense of the diesel Mazda is admirable, the exec stops short of giving us an indication of when the new engine will finally arrive.

Remember that diesel Mazda has been promising? It's coming in the CX-5

Mazda has been talking about bringing a diesel to the US since the current Mazda 6 debuted. It's been delayed, delayed some more, and then seemingly forgotten, but now comes word that the diesel four-cylinder will arrive here in the second half of 2017. It's just coming in the CX-5 first, not the 6 sedan. The diesel in question is Mazda's Skyactiv-D 2.2-liter four, which makes 173 horsepower and 310 pound-feet of torque in other models. Putting it in a small crossover makes some sense, especially considering the recent announcement of a diesel Chevy Equinox. It's good news for choice and another sign that the diesel scandal brewhaha's effect on diesel decisions is blowing over. If it works in the CX-5, we may see this option spread throughout the Mazda lineup. Now if only someone could make a case for that rotary... Related Video: Featured Gallery 2017 Mazda CX-5 View 9 Photos Green LA Auto Show Mazda Crossover Diesel Vehicles mazda cx-5 2016 LA Auto Show