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.

Mazda range-extended EV patent drawing
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. Unfortunately, it’s no guarantee, since the company also patented a new turbocharged rotary engine that seemed suitable for a sports car, but nothing more has surfaced, and the company squashed hopes of a production RX-Vision. Even so, we certainly hope this powertrain reaches production. It’s an interesting iteration of the range-extended EV idea, and production of it would keep our hope for another rotary sports car alive.

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A case for the Eclipse Cross | Autoblog Podcast #508

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Podcasts,Geneva Motor Show,Honda,Jeep,Mazda,Mitsubishi

We recap the recent crop of supercars and Mike advocates for the Mitsubishi Eclipse Cross.

Continue reading A case for the Eclipse Cross | Autoblog Podcast #508

A case for the Eclipse Cross | Autoblog Podcast #508 originally appeared on Autoblog on Fri, 17 Mar 2017 17:30:00 EDT. Please see our terms for use of feeds.

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A tough choice: 2017 Honda CR-V vs. 2017 Mazda CX-5

One has to feel for the typical new-car buyer. The one not reading Autoblog and the one who recognizes a V8 as vegetable juice. For them, picking between compact crossovers must seem like choosing between various identically sized cardboard boxes. Which one do you want? “Ah, I’ll take the one with the best deal.”

Except, with the 2017 Honda CR-V and now the 2017 Mazda CX-5, Joe P. Everyman has a chance to choose between two vehicles that are quite clearly different, yet also clearly leaders in what they do. Everything else seems like alternatives based on price or perhaps off-road readiness (Jeeps Compass and Cherokee, perhaps a Subaru Forester).

As scheduling would have it, a 2017 CR-V Touring just happened to be sitting in my garage the week I was set to drive the new CX-5 Grand Touring in San Diego. This isn’t a complete, scientifically enacted comparison test, but there was enough drive time in close succession on the same roads and with similar price tags to draw conclusions.

At its simplest, the CX-5 is the best choice for the driver while the CR-V is the best choice for everyone else aboard. That’s not to say they are myopic in those classifications – the CX-5 could still ably handle family duty, while the CR-V is impressively well-rounded to drive in a way that shouldn’t turn off those seeking some driving involvement. However, each has a clear focus that sets it down a different path toward different target buyers.

2017 Mazda CX-5 vs 2017 Honda CR-V2017 Mazda CX-5 vs 2017 Honda CR-V

Let’s start with the newer kid on the block from Mazda. It is best suited for the person whose life changes have dictated the switch from an agile car to some sort of family hauler. Its spot-on steering and throttle response evoke Porsche, while the six-speed automatic transmission favors performance over fuel economy (while still getting really good fuel economy). Those dynamic elements, plus a carefully crafted, ideal driving position should make the CX-5 feel “just right” for those used to more sporting, non-family-oriented transport.

Inside, the latest CX-5 boasts a handsome, upscale design with materials to match. Aesthetically, to these eyes at least, it’s the best of a crowded bunch. Quality-wise, only the also-impressive CR-V would seem to come close. Along with the slick new exterior, the cabin conveys the more premium vibe that Mazda was shooting for with the new CX-5 – it also makes a more emotional connection than the typical cardboard box on wheels.

The latest CR-V is less cardboard than ever before, but you’d have to be quite the cubist to prefer its looks over the slinky CX-5. However, the Honda’s rather bulbous rear-end proportions make its unmatched stuff-carrying potential possible. Its 75.8 cubic feet of maximum cargo volume is best-in-class (the CX-5 is down by 5 cubes to 59 cubic feet for 2017) and its low load floor makes lifting in that heavy suitcase or getting the Golden Retriever onboard that much easier.

2017 Mazda CX-5 vs 2017 Honda CR-V

It’s a similar story in the back seat. Honda added two inches of rear legroom for 2017, producing a sprawl-out space for adults and an abundance of clearance for a rear-facing child seat. Even with the driver’s seat pushed all the way back for my 6-foot-3 self, I still had about 3 inches of space remaining in the back. In the CX-5, my knees were grazing the seatback – that’s fine and an extreme example, but worse nevertheless.

Space for smaller items up front is better too, as Honda’s Department of Cubby Bins once again flaunts its talents with a pair of big cupholders and a massive, versatile purse-friendly bin that can be partitioned with a handy, moveable tray.

Technology is a mixed bag for both cars. Honda’s touchscreen receives some much-needed improvements in the CR-V (extra touch-operated menu shortcut buttons, a real volume knob), but it’s still a bit slow to react, going between Apple CarPlay and the Honda systems can frustrate, and the navigation system feels rudimentary.

2017 Mazda CX-5 vs 2017 Honda CR-V2017 Mazda CX-5 vs 2017 Honda CR-V2017 Mazda CX-5 vs 2017 Honda CR-V2017 Mazda CX-5 vs 2017 Honda CR-V

The CX-5 gets Mazda’s standard system with an Audi-like combo of a dash-mounted screen and console-mounted controller (the screen is technically touch-operated, but only when the vehicle is stopped). On the whole it works well, but there are often too many steps required when using the audio system and the controller is placed too far rearward. If you’re shorter, expect to use what can only be described as “dinosaur arms” to reach it. Apple CarPlay and Android Auto are also not available … yet. Mazda says they will eventually arrive and can be retroactively applied to already purchased cars.

Under the hood, you’ll most likely be comparing the CX-5’s standard 2.5-liter 187-horsepower naturally aspirated four-cylinder to the 1.5-liter, 190-hp turbo four found on all but the base CR-V. The CX-5’s is the far more responsive engine, while the CR-V’s is a bit smoother and quieter. But really, both are superb, offering strong acceleration and excellent fuel economy. The Honda is ultimately more efficient, though, likely by two or three mpg combined. You might save about $100 per year on gas.

So there you have it: two crossover SUVs, both class leaders, but in completely different ways. Which is better? That really depends on you. But it doesn’t seem like a stretch to claim that together they sit above the cardboard heap. For Joe P. Everyman, start your search with these two.

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