► Electrogenic MX-5 EV conversion driven
► 160bhp, 228lb ft, ‘plug-and-play’
► It’s faster and cleaner – but is it still fun?
Sacrilege! No doubt the instant reaction of a certain segment of the motoring community when presented with the Electrogenic Mazda MX-5. This is an electric version of the original MX-5, putting a modern – and perhaps controversial – twist on a car that has come to define the classic roadster formula.
Compact, lightweight, front-engined and rear-wheel drive, with the added bonus of a convertible roof, the mk1 MX-5 is celebrated for its accessibility, its tactile nature – and its affordability. Sold in huge numbers, it’s known by enthusiasts as the NA generation of MX-5, Eunos Roadster and Mazda Miata, but I’ll be calling it the mk1 here to avoid confusion with naturally aspirated.
This customer car is proof of concept and highly cherished development mule for a new Electrogenic ‘plug-and-play’ conversion kit that will go on sale later in 2025. I’ve been sent along to drive this electric MX-5 – and meet the UK firm behind it – because I’ve around 15 years of ownership experience across several examples of the original, both standard and modified.
Is this the next step in the evolution of a car that’s already been proven adaptable enough to accept everything from Honda K-series power to thumping V8s, and is renowned for its thriving aftermarket scene? Or does an electric car conversion make the entire experience too anodyne, as some will surely have already concluded? Let’s find out.
At a glance
Pros: lively, highly exploitable performance upgrade, still packed with character, still drives like an MX-5
Cons: no manual gearbox any more (if that matters), a quality conversion is a costly process…
What’s new?
Fundamentally, everything to do with making the MX-5 move has been replaced here. And such is the way Electrogenic goes about things, this has been done without otherwise modifying the base vehicle. Every electric drive component that’s gone in will unbolt again, should a change of heart require it, and the entire vehicle can be put back the way it originally was. This is the same for all Electrogenic plug-and-play conversion kits.
Sounds simple. Isn’t. For there’s not that much room in the engine bay of an early MX-5, and the company and the client were keen to retain the original feel and balance of the car. So while you could fit more batteries in – using the various cavities in the boot, for example – Electrogenic has chosen not to do this.
Other complications include making the original instrument cluster work, retaining – or probably more likely fixing – the air-conditioning, and creating replacements for less obvious critical components. An instance of this in the MX-5’s case is a shortened Power Plant Frame, the torque tube structure that connects the gearbox to the rear differential and helps prevent the car folding in half.
The standard Nardi gearknob remains. But here it’s atop a drive selector, rather than the original five-speed manual. Is that the sound of some narrower-minded purists closing their web browsers?
What are the specs?
Even using Electrogenic’s proprietary battery assembly system – described as ‘super-efficient’, with ‘unrivalled’ energy density – adding 42kWh of capacity under the bonnet and in place of the fuel tank does mean a weight increase. But it’s only by about 30kg compared with this previously 1.8-litre car’s original specification when that fuel tank was full.
Since the new electric motor’s maximum output is 120kW – just shy of 161bhp, almost exactly what my last 1.6-litre Eunos Roadster dynoed at running a full Jenvey individual throttle body conversion, uprated head and cams – according to Electrogenic you still get to enjoy a not insignificant 21 per cent increase in power-to-weight.
What’s more, the crank-rated 228lb ft of torque is double the original figure, and arrives much more immediately. The 114lb ft best of the 1.8-litre petrol peaks at a lofty 5,500rpm…
With the single-speed transmission, which uses Electrogenic’s own reducer gearbox, this all means 0-60mph in about six seconds. That’s roughly two seconds faster than the original (depending on spec). The full 160bhp is only delivered in the Sport driving mode; the Normal setting is equivalent to around 120bhp, Eco around 80bhp – though this retains a sprightliness that belies that modest figure.
Driving range is quoted as ‘150+ miles’ in the real world. This is unsurprisingly going to vary with how you drive it. Charging is via a port fitted under the original fuel-filler flap on the top of the left rear wing. A CCS connection means a full rapid charge is possible in an hour.
Top speed is 115mph.
How does it drive?
The Electrogenic MX-5 starts with a twist of the key, just like the standard car. In fact, it’s two twists, as you first switch it on then – as if priming a fuel pump – pause a moment for the drive system to come online before turning and releasing to make it fully ready to go. You’ll need your foot on the brake here for safety, just like any modern EV.
Keeping the brake pedal covered, you then simply pull back on the gearlever, which engages Drive with a really satisfying mechanical exactness. Accelerate, and you’re off, keeping in mind that like all early MX-5s, the indicator and wiper stalks are the opposite way round.
For insurance reasons – again, this is a customer’s car, with significant sentimental value – I’m not able to drive it on the road. But after a 20-minute passenger ride from Electrogenic’s HQ in Kidlington, I am able to try it at low speeds around the Bicester Heritage site, which gives a sense of the car’s town-friendly behaviour, before heading onto the Bicester Motion test track.
Bicester being Bicester, nobody seems particularly surprised to see a 30-year-old MX-5 moving around to the faint whine of an electric motor – Electrogenic does much of its shakedown and customer sign-off stuff here. But everyone gives it a not unfriendly appraising glance as we glide past.
If you’ve seen it at a Scramble, you’ll know Bicester Motion has far from the largest circuit in the world. But the main straight is easily enough to reach motorway speeds, and the bumpy patchwork surfaces mean it approximates a thrashy b-road rather usefully. Plus, we’ve got the place to ourselves and I’m allowed to run it in both directions. On a cold, greasy January day, it’s more than enough to get a feel for what Electrogenic has achieved.
You might be concerned that some kind of character extraction has taken place with the removal of the explosion factory. But I’m not having that. While the motivation is certainly different – especially without a manual gearbox – this still feels like an immersive, dare I say analogue, experience that’s fundamentally in keeping with the spirit of the MX-5.
For starters, it is very far from silent at speed. This can actually be a problem in some Electrogenic conversions, if customers have expectations of contemporary EV refinement. But in this instance the rising pitch of the motor hum and the threshing of reducer gears and differential is exactly what I want from an updated modern-classic roadster. Due to quirks of the shortened PPF and the harmonics of the motor’s maximum output, it even sounds different in the Sport setting. More purposeful. Wilder. Charismatic.
You could add more sound deadening, but this customer has chosen not to go too far down that route, and I fully approve. The new powertrain has been calibrated to their requirements, too, and while Electrogenic offers an extra-cost tailoring service to every buyer – the software and the Vehicle Control Unit are all its own technology – at first encounter I’m not sensing much I would change here.
Obviously, it’s quite a bit a quicker than a standard mk1 MX-5. People put a lot more than 160bhp into these things, but in Sport this electric Mazda is now rapid and responsive enough that you have to be paying full attention. A slight shudder when you put your foot down hard acts as a warning about the torque-to-tyre ratio even when traction is fully hooked up. The tyres are standard skinny, so it’s a useful reminder.
For daily duties, the softer Eco will do just fine I’m sure, while Normal represents a happy medium that’s particularly appreciable for the additional regen braking it brings over Eco, making considered driving a one-pedal affair. An aspect of the conversion that seems most gratifying, in fact, is how pronounced the difference between these driving modes actually is – this variation helping to further reinstill a sense of character.
Notes include the steering, which is a little heavier than I remember a regular mk1 being – Electrogenic keeps the standard rack but uses an electric pump from an A-Class. The front end of the car is torsionally stiffer due to the EV install basically filling the void there, adding a touch more precision. The centre of gravity is also lower than before. Meanwhile, the regen braking drops off as your speed increases to avoid unbalancing the car at higher velocities.
The handling is otherwise pure MX-5 – which means you’ve got plenty of options. The mk1 has double wishbones and coil-over suspension all-round, and is highly geo-adjustable. This car is on Bilstein dampers of slightly uncertain derivation (the original OEM option being notoriously harsh, which it doesn’t feel here), riding relatively low and rolling only a little in the corners; grip isn’t entirely transparently communicated, but that’s an MX-5 thing, and the front is more tenacious than the rear.
When I do eventually get too eager with my right boot and the back steps out, it’s an instinctive snap to collect it and carry on – also very much an MX-5 thing, even with an open diff. The e-motor’s greater and more instant torque only makes this more accessible. Why complain?
I guess the major point, however, is that I didn’t miss the internal combustion engine at any point during the drive. There’s enough noise and involvement and – yes – speed to make this a properly visceral experience. And while some might mourn the manual gearbox out on the open road, I like left-foot braking. There’s still so much fun to be had balancing the line between handling and grip.
What about the interior?
This is pure, original MX-5 – right down to the tape deck and the cassettes in the central cubby – with two exceptions.
Firstly, Electrogenic uses the original instrument cluster slightly differently. With no modifications to the dials (though this is easily done; you could probably have somewhere like Revlimiter design soemthing) the rev counter now acts as a power meter and the OEM battery warning light signifies the drive system is switched on. The oil pressure gauge functions as a rudimentary fault indicator. A digital screen hidden in the glove box gives more incremental remaining driving range info should the repurposed fuel gauge not suffice.
Secondly, there are two extra knobs: one for the driving mode, the other for this particular car’s bespoke speed limiter system (it lives in London, where limiting the car to 20mph and 30mph specifically is important). Mounted in a 3D-printed panel that sympathetically – if not quite seamlessly – sits in the top of what used to be the central ashtray, these are deliciously tactile to use. Snicking between settings feels like high-end hi-fi and the patterning on the panel closely matches the original finish.
Before you buy
There is, inevitably, a fairly sizeable pachyderm in the corner with this whole business: the cost of the Electrogenic conversion. CEO Steve Drummond tells me he hasn’t quite decided on the price yet – and for what it’s worth, I believe him – but says the kit is likely to be upwards of £30,000. And it will need to be fitted by an approved specialist.
That is, unquestionably, a lot of money to spend on vehicle of the MX-5’s value. Financially, this sort of thing makes more sense on a car like an E-Type, where the cost of an engine rebuild isn’t dissimilar to the cost of making it an EV. But there are an awful lot of mk1 MX-5, Eunos Roadster and Miata owners out there. And it is among the latter in the USA where Drummond expects the most interest – America’s car culture being that much more varied and willing when it comes to engine swaps and the like.
As for the price itself, keep in mind that this is an OEM-grade conversion that will simply bolt right into the car, and should be up and running in 15 minutes once the physical labour is done. Based on proprietary technology, and built from brand new components that are far from cheap on their own, this is never going to be an inexpensive undertaking. While an EV conversion could be done for less, it seems unlikely to me that it could be done this well.
For now, this is plug-and-play for the mk1 MX-5 only. The mk2 – or NB – MX-5 / Eunos Roadster / Miata is a revised (and reinforced) variant of fundamentally the same car, so the same components should basically fit. But additional work is needed to ensure the mounting points and packaging completely agree; Electrogenic is doing similar adaptation for successive generations of Land Rover at the moment, so this isn’t out of the question in the future.
A whole ocean of aftermarket MX-5 chassis enhancements exist, should you wish to go seeking handling nirvana alongside your EV conversion – from upgraded parts through to structural enhancements at varying levels of interference. Be warned, though: I went through five different spring and damper combos on my last one before ending back in a kind of OEM+ situation (albeit with a full Flyin’ Miata butterfly brace); at the very least you’re going to want good bushes.
Verdict
Electrogenic’s implementation of this idea is extremely convincing. The car is great to drive – still – and remains packed with character, albeit of a slightly different kind, while the combination of modern electric tech and the classic Mazda MX-5 platform really works for me. The conversion seems top notch and the integration suitably sympathetic. If you got the inclination and are unfazed by the cost, don’t hesitate.