Next-gen Miata will be 2.5L, NA, and manual - Road & Track Interview with Mazda Execs

https://www.roadandtrack.com/news/a64474059/2027-mazda-miata-next-generation-details/

Great news - Mazda executives seem very committed to the lightweight ethos of the Miata. They also confirm it will remain naturally aspirated "with a forthcoming Skyactiv Z engine, building on the company's experience of compression-ignition lean-burn gasoline powerplants...running in so-called Lambda:1 conditions, using ultra-accurate metering to deliver the optimal stoichiometric fuel-air mixture throughout the rev range." 

“If we go to Lambda:1, then naturally power will go down,” admits UmeE36 M3a. “But in order to avoid that, we have defined the displacement to be 2.5 liters. So the power is very good, and the fuel economy will be very good.”

Good article worth reading.

The profanity filters are biased against Japanese names, evidently. 

Mazda usually does not share any information at all about future product. But it looks like there's some legit information in here and it's from a legit source - be prepared for an avalanche of blog posts with spy shots and renderings, all 100% faked.

Nothing too surprising in here. The Skyactiv Z was pretty much a given. Nobody understands the Miata better than Mazda, so small and light was also a given. 2.5 is actual hard info, that's unexpected.

Miata fans will be pleased to learn that detailed thought is already being given to a fifth-generation version

Well, yes. It's probably going to be introduced in a year or two. I'll bet they've been thinking about it :)

Motor1 points out that the first car with a Skyactiv Z is scheduled to be released in late 2027, which makes me think the next Miata will be a 2028 at the very earliest and more likely a 2029. That's a little further out than I expected.

More than 1.2 million have been made since the original launched in 1989, and it remains at the heart of the brand’s promise of combining affordability with driving pleasure.

That says it right there.  Mazda wants the MX-5 to STILL be the answer.  Something that other manufactures missed with their roadsters.

I read somewhere the Skyactiv Z 2.5 won't make as much power as the current 2.5 - just be more efficient. So it's possible we keep the same power to weight ratio 

I'm here for the Mazda C-Levels sharing a racing MX-5 and knowing who is faster.     That would do a lot of good for other car companies, I think :) 

J_D said:

I read somewhere the Skyactiv Z 2.5 won't make as much power as the current 2.5 - just be more efficient. So it's possible we keep the same power to weight ratio 

You read it in the first post in this thread :) 

“If we go to Lambda:1, then naturally power will go down,” admits UmeE36 M3a. “But in order to avoid that, we have defined the displacement to be 2.5 liters. So the power is very good, and the fuel economy will be very good.”

Moving to a larger engine in a more efficient part of the rev range to trade volumetric efficiency for thermal efficiency under higher duty cycle use is something I've thought a lot about for endurance racing engine selection. This is how Top Gear did their bit where an M3 is more efficient than a Prius when the both driven at the Prius' 10/10ths speed. Engines tend to be displacement limited in some form or another by a regulating (government or sanctioning) body, making this rather uncommon in practice. Being that it trades low duty cycle efficiency for high duty cycle efficiency also makes it generally not as well suited to road car use compared to things like smaller displacement turbo engines... Not to mention being mag-racer 'OMG teh powar/litarz!' flame fodder... But I'm not surprised that Mazda would be the one of anybody working this angle, and am glad to see it heading towards the Miata.

With current engine tech, this also still necessitates limiting use to a much smaller (lower) part of the potential rev range. This 'Lambda:1' tech is especially interesting, as it looks to allow the area of high thermal efficiency to be greatly expanded across not only more of the load range, but also dramatically more of the rev range. Basically it may not have any more power, but will have more torque AND better fuel efficiency... Especially when being driven the way you want to drive for smiles per mile in a classically 'under-powered' sports car.

One interesting thing shown here, is that the Skyactiv X might actually still hold an advantage in a significant amount of driving use, especially steady state highway. In an automatic transmission with electronic throttle, some of this can be mitigated by forcing higher load at lower rpm for the same output requested by the pedal, but not necessarily with a manual transmission. So I'll be curious to see how the manual vs auto EPA numbers come out. If Mazda gets to dictate the driving style, it might be pretty close, but that probably wouldn't be as representative of the typical driver. Either way, even if the Skyactiv Z EPA numbers come out looking like a less-than-impressive upgrade from the current cars, that should only be part of the story. The best part in a Miata may just be the ability to flog it with little-to-no downside.

This excites me greatly.

Not a hybrid? I thought it wasn't going to be ICE-only. A hybrid powertrain could improve the Miata's performance too, they become a lot easier to pass around 150kph on track, so saving some "KERS boost" for higher speeds on the straights could be helpful.

I wonder if the march to stricter emissions will eventually make some of the whacky non reciprocating piston ICE designs more viable finally? I feel like I've seen a couple dozen variations, but they always prove to be financially unviable or just not reliable enough.

Some more worthwhile reading on Mazda's engine and powertrain technologies and strategies:

https://www.mazda.com/en/mazda-mirai-base/articles/20250319-multisolution-skyactivez/

In reply to theruleslawyer :

Mazda's actually been trying a single-rotor as a range-extending APU, they've sold some MX-30s with that powertrain. I doubt other companies will get anything too wacky to work before pure EVs or even turbine generators become better options. 5/6 stroke engines or opposed piston engines have a better chance.

It looks like Mazda is backing off on their electrification plans - IIRC they were saying all Mazdas would be electrified by 2030. Of course, that also includes mild hybrids which is what I expected for the Miata. Just a little assist with a small battery, that can be small and light and effective. But super light? I'm in for that too :)

https://www.autoweek.com/news/a64230531/mazda-ev-strategy-2027-suv/

If we achieve the goal of smaller, lighter, high efficiency batteries, that might open the door for a hybrid Miata. I don't see it happening if the hybrid system makes the car weight anywhere close to 3,000 pounds. That would make it into a totally different car. 

Keith Tanner said:

J_D said:

I read somewhere the Skyactiv Z 2.5 won't make as much power as the current 2.5 - just be more efficient. So it's possible we keep the same power to weight ratio 

You read it in the first post in this thread :) 

“If we go to Lambda:1, then naturally power will go down,” admits UmeE36 M3a. “But in order to avoid that, we have defined the displacement to be 2.5 liters. So the power is very good, and the fuel economy will be very good.”

Forgive my insolence - coffee hadn't kicked in yet hehe

FWIW, the lambda 1 isn't about thermal efficiency, it's about lower CO at WOT.  

The lower power is kind of an indicator of that, as if it was *just* going stoich at WOT, the loss is only about 5% vs LBT fuel- hardly justifying an increase of 25% in displacement.  So the power loss is both fuel and spark knock issues.  

The lowering of CO requirements in the high load test has been known for about a decade in the industry, and has been worked on since 2020 at least.  

Floating Doc (Forum Supporter) said:

If we achieve the goal of smaller, lighter, high efficiency batteries, that might open the door for a hybrid Miata. I don't see it happening if the hybrid system makes the car weight anywhere close to 3,000 pounds. That would make it into a totally different car. 

No need for that much battery. A non-plugin Prius battery from 15 years ago is about 85 lbs, and the Miata is already carrying something like 26 lbs of lead acid that may be redundant. The electric motor could replace the flywheel, which is currently 19 lbs.

That's why I specified mild hybrid, it wouldn't have significant electric-only range. The point would be momentary power boosts and regeneration.

Driven5 said:

This excites me greatly.

Ah YES the age old engineering quantity of "good" lol.

Regarding an electrified Miata, it seems like they are hedging their bets:

UmeE36 M3a says that consideration has been given to a Miata EV, but this is clearly not his favored option.

“If all internal combustion engines were banned, then we would have no choice,” he says, “and of course, our engineering team is studying both ways – battery EV and ICE Miata. But whatever we do, the ICE one is lighter.”

I've read elsewhere that the 2.5 Skyactiv Z will likely be paired to a hybrid powertrain in other applications, probably with an Atkinson cycle. So if they must go hybrid Miata in the near future, they have probably engineered the platform to accommodate. Remember, EV does not necessarily mean EV-only. EV could easily mean battery-ICE mild hybrid, which Mazda has hinted about in the past. 

brandonsmash said:

The profanity filters are biased against Japanese names, evidently. 

Egregious! 

I, for one, am duly offended.

This line cracked me up:

"When I started designing this fourth generation, there was a request from the United States to make the car bigger, and to increase the power of the vehicle,” he says, speaking through a translator. “I said, ‘Do you really want a Harley-Davidson?’”

No, that'd be if we wanted an obsolete, overpriced boneshaker. 

I was driving a 2024 to work today (via 20 miles of twisty rowdy roads to test some suspension, life is rough) and I have no idea how they're going to take 100+ lbs out of this car. I've seen how much effort was put into weight savings on the ND. There's not much fat left. Maybe we'll be back on 15s :)

I have to wonder if they'd use a beefier transmission with the 2.5l. The bigger engine and transmission would add weight...

I don't really understand lambda 1 from the perspective of higher revs. Are emissions standards that restrictive at 7000rpm?

I wonder if they'll build a new platform, or just evolve the ND's?

Bigger engines have larger holes in the block so they're lighter :) If the 2.5 is there to regain lost output, it won't necessarily need a stronger transmission. 

The NB is a mild reworking of the NA chassis, and that pair lasted for 16 model years. The NC got a chassis from the RX8, and it lasted for 10 model years - 13 if you count the RX8. The ND chassis has run for 10 model years and it looks like it'll be around for 2-3 more. So a new platform would be a plausible thing.