Plug-in hybrid option for Mazda MX-30 includes the return of the rotary engine – but not necessarily how you’d think
The limited 124 mile range of the Mazda MX-30 electric crossover has been addressed by Mazda in the eccentric kind of way that only it knows how. The new Mazda MX-30 R-EV is a range-extended plug-in hybrid (PHEV) with a rotary engine under the bonnet, which acts as an electricity generator only, it never drives the wheels directly. The BEV remains on sale alongside it.With a 17.8kWh battery, half the size of the pure electric version’s, the MX-30 R-EV has an electric-only range of 53 miles. Various drive modes can either deplete the battery to zero as an EV, run as a hybrid to a preset 45%, or maintain (or charge to) any battery increment from 20%-100%.Mazda is the only manufacturer to make a long-term success, though it has generally been a niche one, of the rotary engine, in which a triangular-shaped rotor spins around a central output shaft, within a fixed oval-shaped block, creating three combustion chambers as it spins. Each chamber completes one combustion cycle – intake, squeeze, bang, exhaust – per turn. So with one rotor, as here, which has a combined 830cc capacity between the three chambers, you in essence have a small-capacity three ‘cylinder’ (though they’re not cylindrical) engine. Because the movement is always rotational, there’s no reciprocating motion, so it’s very smooth.Previous Mazdas have had multiple rotors (the RX-8 had two, the 787B Le Mans winning racing car had four), each adding three chambers (like cylinders but not cylinders) to the mix. Hence the four-rotor (twelve-chamber) 787B screamed like a V12 and then some at 8500rpm.Kota Matsue, the general manager of Mazda’s powertrain division, has had to explain to otherwise knowledgeable Mazda insiders – I gather to some disappointment – that this famous noise wouldn’t be accompanying a single-rotor generator that tends to run from 2300rpm to 4500rpm. But, he says, the advantages are that it’s lighter and more compact and smoother than an equivalent four-stroke engine, and that the output shaft is in the middle of the block, which is where you’d want it to drive the generator it’s bolted to. Plus it’s nicely weird.Anyway this rather complex unit all sits transversely beneath the bonnet, as does the drive motor, which powers the front wheels. The 50-litre fuel tank sits beneath the floor, along with the reduced battery, which can take DC charge at a maximum of around 36kW, but is only little so charges quite quickly.The rotary engine makes 74bhp but that doesn’t matter because it never drives the wheels directly. The electric drive motor makes 168bhp, but the battery output can’t quite keep up with that, so in hybrid mode under hard acceleration the engine and generator pitch in to make up the difference (or even in EV mode, if you wilfully pass the throttle’s kick-down stop). As a result, the 0-62mph time is 9.1sec, rather than 9.7sec for the 143bhp pure BEV MX-30. If all this sounds complicated, and I suppose it is, as a driver you don’t need to know it. You just set the drive mode and away you go, as an EV if you like on the daily commute, with the backup range for visiting gran at weekends. Shift paddles change the retardation level, and mostly it hums along electrically and smoothly with, under acceleration, the occasional distant mid-range whirr of a rotary engine being run at full load, sounding a bit like somebody running a masonry drill three-doors down.Like the EV MX-30 it’s quite good fun to drive, with suspension that’s both comfortable enough around town yet controlled enough to give it a bit of pep on the open road. The plug-in hybrid is 131kg heavier than the EV. And I like the interior. There’s a rotary controller for the top touchscreen and some quirky, quite cool material choices, like cork and a padded leather. The car has some character – like rear doors you can only open when the front ones are – to which the drivetrain only adds.On a drive like ours, of several short loops from various charge levels, and while trying all the different modes, it’s hard to keep tabs on the exact efficiencies, but like most PHEVs it’s variously less efficient than either a pure EV or a pure combusted car: 53 electric miles is under 3mpkWh; maintaining a constant battery level I saw around 34mpg. Don’t buy this car if you want outright efficiency, but do consider it if it’s the convenience that matters more. Given the pure BEV has a small battery it’s (relatively) affordable, with prices from £31,250. The R-EV has the same trim levels and same prices too (slightly more expensive top trim aside), but with 21g/km of CO2 at the exhaust and an 8% rather than 2% benefit-in-kind tax rate of the BEV.Mazda knows the electric MX-30 is a niche choice, given it’s a 4.4m long crossover with suicide rear doors, small rear seats, and a little battery. But it’s finding that those who it does suit, it does so well. The plug-in hybrid version will broaden the range appeal – a little – while remaining endearingly odd.
