The Mazda MX-5 Miata has always strictly followed the lightweight sports car ethos born from British roadsters of the ’50s and ’60s: A revvy, simple, naturally aspirated four-cylinder up front, connected to a manual transmission sending power to the rear wheels, nestled in a two-seat convertible body.
The formula works for a few reasons. Its simple nature means there isn’t a lot of weight or complexity involved. Done right, it delivers an incredible balance, which results in a thrilling drive. And because it’s so simple, it costs relatively little to get into, and next to nothing to maintain.
This approach has proved successful for Mazda. The Japanese carmaker has sold well over 1 million Miatas over 37 years and four generations, making the smile-inducing two-seater one of the greatest-selling sports cars of all time.
There was a time, however, when Mazda briefly looked at switching the formula up by adding more weight and power, in the form of a V6 engine. Engineers even went as far as secretly building a prototype. Thankfully, the automaker quickly realized this would’ve just made the Miata worse, not better, and dropped the idea.
The Factory V6-Powered Miata Was Real, For A Moment
Dutch news site AutoRAI.nl recently got a chance to speak with Christian Schultze, the director of research and operations of Mazda Europe, about the Miata’s future. When the conversation drifted towards powertrain possibilities, the publication asked about whether the next Miata, expected to be named the NE internally, might get a 2.5-liter engine (the current Miata has a 2.0-liter engine, so this would be a big step up in capacity). Schultze revealed something I don’t think anyone was expecting: Mazda had already experimented with a 2.5-liter engine, in the form of a V6. From the story:
A 2.5-liter engine sounds appealing, I understand. But interestingly enough, we already tried something like this about twenty years ago. Back then, our engineers built a prototype with a 2.5-liter V6 in their spare time. They did it here in the workshop, purely out of enthusiasm.
Though Schultze doesn’t go into detail about the car itself, 20 years ago would peg this experiment as having happened around 2006, a year after the NC-generation Miata made its debut. There’s no official word on which 2.5-liter V6 was used, but those who know their Mazdas know that the company made a V6 called the K-Series in various displacements up until the early 2000s, the most powerful of which we saw in the states, the KL-DE found in the MX-6, made 164 horsepower and 160 pound-feet of torque. There was also a version that made around 200 horsepower, but it was only sold in Japan.
Compared to the 170-hp four-cylinder found in the NC Miata, this would’ve been a notable step up in performance. But you don’t just get something for nothing, as Schultze pointed out to AutoRAI:
Technically, it was a fascinating project. The problem, however, was the packaging. The engine didn’t fit well under the hood; it was simply too high. The result wasn’t visually appealing. But in terms of the driving experience, it was definitely interesting. That shows that the idea itself isn’t new.
Of course, more power is always good, so it probably wouldn’t have been hard for designers to engineer around the extra height. But a bigger engine also means more weight in the nose. And weight, according to MX-5 engineers, is the ultimate foe. In the case of the MX-5, power isn’t the ultimate goal. It’s lightness. From Schultze:
The real question is: what do you need that 2.5-liter engine for? Is it for the extra torque? Is it for better emissions? Or is it primarily attractive because it’s a larger engine? We want a lightweight engine. A 2.5-liter is by definition heavier than a 1.5- or 2.0-liter. Extra weight up front directly affects balance and steering response. These are precisely the elements that make the MX-5 so special. So it’s not an easy choice.
Weirdly, this might not be the only V6-powered Miata prototype built by Mazda, at least going by Miata.net. Back in 2001, Mazda USA allegedly let Road & Track Magazine drive an NB Miata powered by a 3.0-liter Ford Duratec V6, which it wrote about for a print issue. While the print article never made it out of the magazine’s pages, Miata.net claims the car used RX-7 brakes, an RX-7 transmission, and an RX-7 differential to handle the extra twist.
All of that extra equipment makes sense. Adding a bigger, more powerful engine raises more problems than just weight. Because the car is now faster, it needs more tire, more suspension, and more brake to keep up. All of the drivetrain components have to be beefed up to handle the extra twist, and the body has to be modified to accept a wider track. While all this stuff would likely end up improving lap times, the extra weight would compromise that original roadster ethos that made the Miata so successful.
You could argue a Miata with a V6 is a better car, but it’s definitely a worse Miata. The Miata isn’t great because it’s fast. Anyone who’s driven an MX-5 will admit they are decidedly not fast. Miatas are great because they’re balanced, lightweight, communicative, and cheap to own. Could Mazda engineer a V6-powered Miata that’s also fun? I have no doubt. But it wouldn’t be as fun or usable as the original.
No Shortage Of Aftermarket Firms Can Do It For You
If you somehow come away from the first portion of this article thinking the only thing the Miata needs to be perfect is a V6, I wouldn’t count on Mazda to make it happen. That experiment was 20 years ago, and there hasn’t been any indication since that Mazda will use anything other than a naturally aspirated inline-four for the upcoming NE. But there are a few third-party firms that offer swap kits if you want to make your V6 Miata dreams a reality.
V8Roadsters, a US-based aftermarket parts firm that specializes in Miata engine swaps, makes swap kits for all generations of Miata that include new subframes and engine mounts, designed to accommodate General Motors’ LFX V6, which was originally used in cars like the Camaro and the Cadillac ATS. UK-based firm Rocketeer makes parts to fit Jaguar’s AJ30 V6, which appeared in cars like the XJ, the XF, and the Lincoln LS. Pay them enough money, and they’ll build you a whole resto-modded NA or NB, complete with a V6 swap.
Me, though? I think I’ll stick with the original formula.
Top graphic image: Mazda
“A 2.5-liter is by definition heavier than a 1.5- or 2.0-liter.”
I remember an interview – I think it was with Duntov- that justified bumping up the 427 in the Corvette to a 454 because it removed the weight of 30 (ish) cu. in. of metal from over the front wheels…
No need for “educated guesses” about the legend of the prototype V6 Miata built by Mazda – and it seems that “Christian Schultze, Mazda’s European Director of Research and Operations” is also guessing (he’s wrong in most of his statements about this). Road & Track ran a story about it in their September 2001 issue – cover caption “First Drive: Mazda’s V-6 Miata”; pages 66 and 67 have the story. It used a Lincoln 3.0 version of the Duratec V6, in an NB chassis (not an NC, that was 4 years before the NC). While that never made it to production, the concept lives on with the Rocketeer Cars (UK) conversion kits and restomods using the Jaguar S-Type version of the same 3.0 V6, for NA and NB Miatas (soon to be available for NCs).
The 3.0 engine fit just fine in the 2001 prototype, it was lighter than the iron block 1.8 4 cylinder used in the NA and NB, it was only the prototype’s use of the stock intake manifold that required a modified hood. As Rocketeer demonstrates, a custom intake manifold on the V6 fits perfectly well under the stock hood!
A Miata.net Forum member came across the V6 NB Miata twice in 2001, and wrote about it with additional photos and comments from a discussion with the two Mazda development engineers in a Miata.net news article in 2001. It can be found on the Miata.net site in the News section, titled ‘V-6 Miata Concept’.
Cheers,
Gordon
No need for “educated guesses” about the legend of the prototype V6 Miata built by Mazda – and it seems that “Christian Schultze, Mazda’s European Director of Research and Operations” is also guessing (he’s wrong in most of his statements about this). Road & Track ran a story about it in their September 2001 issue – cover caption “First Drive: Mazda’s V-6 Miata”; pages 66 and 67 have the story. It used a Lincoln 3.0 version of the Duratec V6, in an NB chassis (not an NC, that was 4 years before the NC). While that never made it to production, the concept lives on with the Rocketeer Cars (UK) conversion kits and restomods using the Jaguar S-Type version of the same 3.0 V6, for NA and NB Miatas (soon to be available for NCs).
The 3.0 engine fit just fine in the 2001 prototype, it was lighter than the iron block 1.8 4 cylinder used in the NA and NB, it was only the prototype’s use of the stock intake manifold that required a modified hood. As Rocketeer demonstrates, a custom intake manifold on the V6 fits perfectly well under the stock hood!
A Miata.net Forum member came across the V6 NB Miata twice in 2001, and wrote about it with additional photos and comments from a discussion with the two Mazda development engineers in a Miata.net news article in 2001: https://www.miata.net/news/v6.html
Cheers,
Gordon
Brian, a former R&T editor – you missed the research from your former magazine! Then again, it seems the Mazda engineer (“Christian Schultze, the director of research and operations of Mazda Europe“) is also unaware of his own company’s history. No, it wasn’t an NC project, and it wasn’t a 2.5 V6. No need to guess, either – Road & Track ran a story about it in their September 2001 issue – cover caption “First Drive: Mazda’s V-6 Miata”; pages 66 and 67 have the story. It used a Lincoln 3.0 version of the Duratec V6, in an NB chassis. While that never made it to production, the concept lives on with the Rocketeer Cars (UK) conversion kits and restomods using the Jaguar S-Type version of the same 3.0 V6, for NA and NB Miatas (soon to be available for NCs). (As mentioned in the article – same engine Mazda used in 2001!!!)
As mentioned by a few commenters, a Miata.net Forum member came across the V6 NB Miata in 2001, and wrote about it with additional photos on a Miata.net news article in 2001. He took a bunch of pictures of the prototype, and talked with the engineers who had it out for a drive:
https://www.miata.net/news/v6.html
Cheers,
Gordon
Huh, fascinating! I’m shocked I didn’t know about this R&T article before I wrote this, guess it was before my time. The differences in the NB and the car described by Schultze make me think they might even be two different cars. Either way, I’ve updated my article to reflect the NB’s role in this
I don’t know if it still exists, but here in north Georgia there was a company installing Acura 3.0 and 3.2 Liter V6s into Miatas. You could either bring your own for conversion or they would find a good one for you and sell you the whole car. I saw them at The Mitty at Road Atlanta a while back.
This might be a wild question, but I wonder if anyone’s every tried doing a LV1/LV3 swap into a Miata? If an LS can fit, it’d be hard to imagine the V6 version wouldn’t, and it’s nearly the same in weight but much more power than a Mazda 4-banger, and with the aftermarket, I bet-ya you could get a 7,000rpm capable version pretty easily.
Maybe they just tried the wrong engine. I’d like to see them try again, maybe with a bored and stroked BMW I6 motorcycle engine….and blackjack..and hookers.
In fact forget the blackjack.
I’d bet it was an NB not an NC, especially if they used a Mazda K. The rocketeer kit has sounded super cool ever since it came out but ultimately I think I’d rather have the slow car fast feelings.
I’d love to see how the little 3-cylinder turbo from the GR Corolla fits. It can’t weigh that much.
MiniTec makes a Honda V-6 conversion kit for the Miata. 250hp in the base version out of an Odyssey for example.
I’m gonna say you can add power and end up with what’s still very much a Miata. It’s not a lack of power that defines the car. And that’s based on years of actual experience with a lot of different Miatas.
Mazda’s done a few science experiments over the years, including a hydrogen rotary Miata. But they have a clear idea of what the Miata is, so they have managed to stay true to their original concept. Just don’t forget there was a modified Miata on the stand the day the car was introduced to the world. Modification is baked into its DNA.
It’s not the power, it’s the balance and handling that define the Miata. And bigger engines ruin that. I’ve read about a bunch of engine-swapped Miatas over the years, and the builders all say the same thing: the car is now way faster in a straight line, and a complete pig in corners.
But they don’t actually ruin it. See, I’ve actually driven a bunch of engine swapped Miatas over the years on the street and on the track. I’ve raced them in tarmac rallies. I’ve got significant seat time in a V8-swapped ND Miata that has a better front/rear balance than the Fiat 124 Spider that was based on the same chassis. And all the journalists who drove it commented on how the handing was not ruined, it was just a Miata that had the ability to bend time. “complete pig” was never in the conversation. I will happily provide links if you’d like.
Can you ruin a Miata (or any other car) with a poorly executed engine swap? Yes, definitely. Will you for sure ruin it? Hell no. You may be thinking that all engine swaps are chunky old carbureted iron block V8s with an overstressed T5 bolted on the back. That may have been the case in 1990, but this century has seen a whole bunch of much better options hit the streets.
https://www.miata.net/news/v6.html
In the early ’90s there was a shop in Escondido, CA called Monster Motorsports. They would take the NA Miata and put the Ford 5.0 in it as well as the Thunderbird rear-end. They were sanctioned by both Ford and Mazda (as Ford still has a 25% stake in Mazda) You could actually order one from a Mazda Dealership and retain the factory warranty. I lived in one city over and would see them occasionally. They then optioned the Mega Monster Miata where they threw a supercharger on the 5.0.
I recall a guy in the Detroit area some years ago put a Vette engine in one and had the license plate “IT FIT” or something like that. I assumed the car was uncontrollable if you put your foot down – though the engineers around here sometimes pull it off.
“20 years ago would peg this experiment as having happened around 2006, a year after the NC-generation Miata made its debut. There’s no official word on which 2.5-liter V6 was used”
My guess is that it would have been based off the Ford Duratech V6.
By 2006, the K series V6 would have been out of production for 4 years. And the V6 Mazda was using were all based off the Duratec… like the V6 used in the 2002+ Mazda6, the Tribute or 2nd gen MPV
So, what he’s saying is, Mazda needs a flat 6? Would something from PZL Franklin work?
Nah… it needs a Radial 6
“I bet it would get high gallons per mile.”
“You mean miles per gallon?”
“I said what I said.”
Oops, my brain processed that as ROTARY six.
Yes, radial six for sure. And do it WWI style, where the jugs spin and the crank is stationary
“Oops, my brain processed that as ROTARY six.”
That would be a GREAT idea as well… for Mazda… LOL
Radial engines need to have an odd cylinder count. The only way to promote evenly timed power strokes is to fire every other cylinder in rotation order. If it were an even number of cylinders, you’d have a skip or hesitation.
https://en.wikipedia.org/wiki/Anzani_6-cylinder
Technically, that’s two 3-cylinder radials in a row, but yeah.
Why no mention of the Madzaspeed turbocharged Miata from 2004 and 2005? That engine had similar torque and hp numbers to the 2.5 V6 and weighed less.
Maybe they sell a second sports car that does focus on power and weighs more? This does not have to be an either/or proposition and for the life of me I can’t understand why Mazda wouldn’t give their customers what they want. The enthusiast community has been asking for it for decades.
I would guess the reporter’s question was in reference to the 2.5 liter 4 cylinder found in the previous generations of the Model 3. That might be the most common swap and all reviews I’ve read loved it.
They could call it the RX-7!
Meanwhile Suzuki was playing with a 1.6L twin turbo V8 in their C2 roadster concept.
Suzuki not doing a Cappuccino and developing the C2 concept into a production car with that mad engine ranks as one of my Top 10 Lifetime Disappointments.