Auto blog

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.

Autoblog Podcast #396

Episode #396 of the Autoblog Podcast is here, and this week, Dan Roth, Steven Ewing, and Chris Paukert talk about the 2016 Mazda MX-5 Miata, the 2016 Jaguar XE, and the 2015 Lexus RC. We start with what's in the garage and finish up with some of your questions, and for those of you who hung with us live on our UStream channel, thanks for taking the time. Check out the rundown below with times for topics, and you can follow along down below with our Q&A. Thanks for listening!
Autoblog Podcast #396:
Topics:

2018 Mazda CX-5 is the only IIHS Top Safety Pick Plus compact crossover

We've highlighted a number of vehicles tested by the IIHS, and specifically ones that come up just a little short of being lauded with the organization's highest safety rating of Top Safety Pick+. The reason most of these vehicles fall short is sub-par headlights. But this time we have a different story. The 2018 Mazda CX-5 actually snagged the coveted award, and impressively, it's the only small crossover SUV the organization has tested to earn it. The reason of course hinges on headlight performance. In order for a vehicle to get the award, it has to have headlights available that score a "Good" rating, in addition to having stellar crash tests. The award for good lighting and the Top Safety Pick+ only goes to the CX-5 with the optional adaptive lighting system available on all trims (optional on the base Sport). The standard headlights on the Sport model earned the second-highest rating of "Acceptable." The CX-5 also earned a "Good" rating in every crash test, including both small-overlap tests. It earned 5 out of 6 points in forward collision prevention, netting a "Superior" rating. There are many safe options in the small SUV category besides the CX-5, though. The Honda CR-V, Hyundai Tucson, Kia Sportage, Mazda's own CX-3, and Mitsubishi Outlander match the CX-5's straight-"Good" crash test ratings. They all also pick up an additional forward collision point in the collision warning category. The best headlights any of them can offer, though, are just "Acceptable," and the standard headlights can be even worse with "Marginal" or "Poor" ratings. Related Video: Featured Gallery 2017 Mazda CX-5: First Drive View 25 Photos News Source: IIHS, MazdaImage Credit: Mazda Mazda Safety Crossover SUV consumer mazda cx-5