Mazda Revives Rotary Engine To Extend EV Range, But EU Ban Looms

Mazda’s revival of its iconic rotary engine as a battery-replenisher for a version of its electric car provides an alternative to pure EVs and plug-in hybrids but will eventually fall foul of an EU ban.

By 2035, the EU has banned hybrids, plug-in hybrids and almost everything with an internal combustion engine (ICE). This decision will astonish its citizens who drive limited daily miles and who would hardly ever use the despised ICE, but want the freedom to hit the highway and head for the sun once a year without range anxiety.

Plug-in hybrid electric vehicles (PHEVs) use bigger batteries than regular hybrids and provide electric-only range of up to 60 miles. The battery can be recharged independently. The Mazda MX-30-R-EV’s 830cc rotary engine charges the smaller battery and never powers the car directly. The battery can be charged independently.

Even the radical green regime at the California Air Resources Board (CARB) concedes that poor people living in rural areas might not be able to afford BEVs and want this PHEV flexibility to remain when its ICE ban kicks in, also in 2035. Many U.S. states will follow the CARB’s advice.

Mazda of Japan has added a little rotary engine to an MX-30 battery electric vehicle (BEV) to extend the range and the bare numbers are very impressive. The small, 17.8 kWh battery can manage a claimed 53 miles before the rotary engine needs to cut in and generate electricity. The little ICE engine can provide enough juice for 350 battery miles, alllegedly. The MX-30 R-EV, is always powered by the electric motor. Range anxiety is a thing of the past. The system produces only 21 grammes of CO2 per kilometer.

The drive by politicians in Europe and the U.S. to declare they know better than engineers that electric cars, to the exclusion of all else, are the best way to reduce global carbon dioxide (CO2), will waste valuable and proven resources provided by ICE linked to batteries and hybrid technology, according to expert engineers like Kelly Senecal of the U.S.

That’s one of the conclusions of the book “Racing Toward Zero – The Untold Story of Driving Green” written by Senecal and Felix Leach of the U.K.

Hybrids, PHEVs, and now this Mazda rotary engine solution, use small batteries compared with huge BEV batteries, and avoid consuming large quantities of scarce and likely ever more expensive commodities like lithium, nickel, cobalt and copper.

They also offer a more affordable option. If battery-only electric cars come to dominate the market, this is likely to price average earners out of their cars.

Asked to comment on the potential of the Mazda rotary plan, Senecal reiterated his support for PHEVs and also pointed to the gap in the EU regulations for 2035 which allow carbon-neutral ICE fuel.

“Banning plug-in hybrids would eliminate a potentially ideal solution for many drivers in Europe,” said Senecal, in an email exchange.

“PHEVs provide the freedom to drive without tailpipe emissions in city centers while maintaining the flexibility and range of an internal combustion engine for longer distances. Pair a PHEV with a renewable, carbon-neutral fuel, and you have what may be the best option available today for both consumers and the environment,” Senecal said.

Green lobby organizations like Brussels-based Transport & Environment disagree.

T&E didn’t respond to a request for comment, but in a report published this year, “Plug-in hybrids: A dangerous distraction”, it said PHEVs shouldn’t get tax breaks from governments because they don’t contribute to CO2 reduction and can even make it worse.

T&E has a good point when it says that company car drivers often have no incentive to use the battery-only range, so the increased weight of the PHEV makes its overall fuel efficiency worse than an ICE vehicle. This could be solved with geo-fencing, which would penalize non-use of the battery-only range.

But this criticism makes little sense for private buyers with small average annual mileage, not convinced by the efficacy of battery-only vehicles (BEV), and who would be denied a vehicle which, for maybe 90% of use, would be electric only.

Meanwhile in China, a report from Fitch Ratings said PHEVs are seen as a “key catalyst” in the transition to EVs. Fitch said PHEV sales in China will continue to show fast growth because they are seen as close substitutes for traditional ICE vehicles, as drivers are not affected by range anxiety or charging inconvenience.

Pedro Pacheco, senior research director at Gartner Group, thinks the 2035 EU ban would make sense if a reliable BEV charging network existed, but doesn’t hold out much hope.

“Banning PHEVs by 2035 makes a lot of sense if the EU takes the right steps to enable a full-proof EV charging experience to all drivers by then,” Pacheco said.

“(CO2) Emission regulations will have to be progressively tightened in order to prompt (manufacturers) to progressively steer more resources into BEV development. However, at the moment, I feel the EU is currently failing in these two areas and less sensible regulatory decisions taken by some countries also don’t help.”

Pacheco said there wasn’t much chance of the charging network getting up to scratch.

“Currently I don’t see a compelling set of measures that will succeed at making the EV charging experience radically better and the recent ‘softening’ of Euro VII regulations is also contrary to the logic of progressively tightening emission regulations.”

“We may be heading into a situation where, by 2035, EV charging may not be on par with the needs of many drivers and not all (manufacturers) will be putting enough commitment in developing top-notch BEVs. Such a scenario would make a 2035 ICE ban something hard to cope for some car buyers,” Pacheco said.

Between the launch of the Mazda Cosmo in 1967 and production of the RX-8 ending in 2012, Mazda produced close to 2 million rotary engines. The rotary engine was thought to be extinct because for all its advantages – lightness, smoothness, quietness – that didn’t include fuel efficiency. But this latest iteration, scaled down and running at constant speed, has given it a new lease of life. Unfortunately, at least its days in Europe are numbered by the 2035 ban.

According to investment researcher Jefferies, European PHEV sales peaked in 2022 at just over 1 million, will stay around that level through 2025 before sliding to 800,000 in 2030 and 700,000 in 2035.

Mazda MX-30 R-EV

17.8 kWh lithium-ion battery

ICE 168 hp, 830cc rotary engine

I-speed automatic

0-60mph 8.9 seconds

Top speed 87 mph

Miles per U.S. gallon 339.3 (claimed)

Battery range 53 miles (claimed) + 350 miles ICE assisted

CO2 – 21 g/km

Price – from £31,250 after tax ($39,000)