Japanese Engineers Explain Why These Engines Will NEVER Be Built Again

In 2010, engineers at Lexus finished an engine that revved so fast an ordinary needle couldn't track it, so they fitted a digital gauge instead. They built exactly 500 and then they closed the line. That engine will never be built again, and neither will most of the engines on this list. Tightening emissions rules, the cost of building by hand, and the shift to electric power have quietly ended a whole era of Japanese engineering. These are 10 engines the industry can't or won't make anymore, and the real reasons they're gone. Nearly all of them come from one strange window in history. Through the late 1980s and the 1990s, Japan's carmakers were locked in a quiet arms race, held back only by a voluntary agreement to cap official power at 276 horsepower. So instead of chasing bigger numbers on the brochure, they spent the money on the engineering underneath. You're about to see where that money went. 10. The Mitsubishi 4G63 On paper, it's an unremarkable thing. A 2.0-liter turbocharged four-cylinder with a cast iron block, an engine that also did duty in ordinary Gallants and the Eclipse Coupes sold across America. But that heavy iron block is exactly why it became a legend. Bolted into the Lancer Evolution, it carried the Finnish driver Tomi Mäkinen to four straight World Rally Championship driver's titles from 1996 to 1999, trading blows with Subaru on gravel and snow stages around the world. It was an old-fashioned design even then, a belt-driven iron four with none of the exotic metals you'll see further up this list. And that plainness was the whole point. On the street, Mitsubishi rated it at the capped figure everyone quoted, though the real number sat higher, and a handful of special UK editions eventually admitted to more than 400 horsepower straight from the factory. Because the block was so overbuilt, tuners found it would hold together well past 1,000 horsepower, with some drag-built examples clearing 2,000. Think about that for a second. A rally sedan engine, standing up to numbers that would tear most supercars in half. When Mitsubishi launched the Evo X in 2007, they retired the iron 4G63 for a lighter aluminum design, one developed jointly with Hyundai and Chrysler to share costs across companies, which tells you plenty about where the industry was already heading. By 2016, the Lancer Evolution was gone entirely, with no successor and no plans for one. For a stretch of the late 1990s, half the car magazines on the newsstand had a Lancer Evolution or an Impreza on the cover, sliding sideways through a forest. That world, of four-door rally cars turned into road cars and sold to anyone with a license, has simply ended. The whole reason this engine existed was homologation, building a road car so the racing version was legal for a rally championship Mitsubishi no longer contests. Take away the racing, and there's nothing left to justify an engine built like this. 9. The Subaru EJ20 Subaru's answer to the 4G63 was this flat-four turbo, and for a decade the two engines defined rallying for an entire generation of fans. The EJ21st appeared in the 1989 Legacy and ran for a remarkable 30 years. Its horizontally opposed layout gave Subarus their low center of gravity, and, thanks to unequal-length exhaust headers on the early cars, that uneven, burbling rumble you could pick out with your eyes closed. It carried the Scottish driver Colin McRae to Subaru's first world rally championship in 1995, won two more world titles across the following decade, one of them with the Norwegian driver Petter Solberg in 2003, and pounded around the Nürburgring 24 hours for years. Part of what made those cars unforgettable was the noise, a lopsided thrum that came from the way the exhaust runners met the engine, an accidental signature nobody set out to design. Over time, the engine simply became the brand. Then in 2019, Subaru announced it would end EJ20 production the following March. To mark the moment, they built the WRX STI EJ20 Final Edition, just 555 cars for the Japanese market, sold by lottery, the number itself a nod to the old blue-and-gold rally livery. The larger 2.5-liter version soldiered on in America for one more year before the STI vanished there too. Nobody said the reason out loud, but it was plain. The boxer engine that made Subaru distinctive was expensive to build, awkward to keep clean under modern emissions testing, and the company had already designed a newer family of engines to take over. The replacements are quieter, smoother, and easier to certify. They also don't sound like anything in particular, which is the trade. When the last EJ20 left the line, a piece of Subaru's character went with it. 8. The Mazda 20B This is the rarest engine here, and one most people have never heard running. It's a rotary, a wonkle, with no pistons at all, just triangular rotors spinning inside their housings. And uniquely, it had three of them. The 20B is the only mass-produced three-rotor engine the world has ever seen, and it lived in exactly one car, the Unos Cosmo, a bubble-era luxury grand tourer Mazda sold from 1990 to 1995. Only around 5,000 were ever built. By the standards of 1990, it was staggeringly expensive, a rolling technology showcase meant to prove Mazda belonged in the same room as Mercedes and BMW. The Cosmo was extravagant even for its moment, one of the first cars anywhere to offer a built-in touchscreen with satellite navigation. And beneath that long hood sat this impossibly smooth triple rotor, breathing through a sequential pair of turbochargers and making around 300 horsepower. A rotary is also tiny and light for its output, which let Mazda's designers sit it low and far back in the car for near-perfect balance. It spins with almost none of the shaking a piston engine fights, so at speed the Cosmo felt less like a car with an engine and more like a jet idling on a taxiway. But that smoothness came with a bill. Rotaries drink fuel, they burn oil on purpose to survive, and they lean on tiny apex seals at the tips of each rotor that slowly wear and eventually fail. Those same traits made the engine punishing to certify as emissions rules tightened through the 1990s, right as Japan's bubble economy collapsed and the money for extravagant projects dried up. It sold in tiny numbers, and Mazda built the three-rotor once, learned exactly how hard it was to sell and to keep legal, and never attempted another. It stands as a one-of-one experiment from a moment when a Japanese company had enough confidence and enough cash to try almost anything. 7. The Honda F20C In 1999, Honda dropped an engine into its new S2000 roadster that read more like a superbike spec sheet than a car's. Two liters, no turbocharger, and a redline of 9,000 RPM. It made around 240 horsepower with no forced induction at all, which worked out to roughly 125 horsepower for every liter of displacement. In plain terms, no mass-produced naturally aspirated engine on Earth made more power for its size, and it held that record for 11 years, until Ferrari's 458 finally edged past it in 2010. It's not a typo, by the way. A Honda roadster you could buy from a normal dealer outspecced most of the supercar world on paper, and it won a spot on Ward's list of the 10 best engines two years running. Honda had essentially handed the public a detuned racing engine and asked it to survive 100,000 miles of commuting, and somehow it did. The trick was VTEC, Honda's system for switching to wilder camshaft profiles high in the rev range, backed by fiber-reinforced cylinder walls that let the little four survive daily life near the redline. The engine felt almost sleepy until around 6,000 RPM, then changed character completely and screamed to 9 grand, pulling harder the higher it climbed, which is the reverse of how a modern turbo engine feels. Honda still calls it the high point of their naturally aspirated engineering, and that's exactly why it can't come back. An engine that makes its power right at the top of the rev range burns more fuel and emits more to get there, and modern rules quietly punish precisely that design. The industry answered with small, turbocharged engines that deliver their torque low and early. Even Honda softened it, giving the follow-up 2.2-liter version more everyday muscle and a lower ceiling. The pure, screaming original lasted only a few short years before the S2000 itself ended in 2009. 6. The Honda NSX engine, the C30A When Honda set out to build a car that could humble Ferrari, they decided the engine had to materials no road car had used before. Honda benchmarked the whole car against the Ferrari 348 and set out to beat it on reliability and everyday ease, and the engine was where they made their statement. The NSX's 3-liter V6 became the first production engine anywhere to run titanium connecting rods. Titanium is lighter and stronger than steel, which let the engine spin cleanly to 8,000 revolutions per minute without shaking itself apart. And it paired those rods with forged pistons and the first VTEC system ever fitted to a V6. The bodywork was just as bold, the first mass-produced car built around an all-aluminum frame and finished in a 23-step paint process. That aluminum body alone was a small revolution, shaving off weight most rivals still carried in steel, and it took Honda years to learn how to weld it reliably at scale. But the part that matters most for this list is how it was made. Every NSX was assembled by hand at a purpose-built plant in Takanazawa by a team of roughly 200 of Honda's most experienced people, each with at least 10 years on the job, turning out only about 25 cars a day. These were people who had spent years just qualifying to be allowed near that line. The Formula One champion Ayrton Senna helped tune the chassis at Suzuka during development, telling engineers the body needed to be stiffer. Around 18,000 NSXs were built over 15 years, an everyday supercar screwed together by master hands and sold at a price ordinary people could reach for. When Honda finally revived the NSX years later, it didn't try to repeat any of this. The new car used a twin-turbo hybrid system instead, because the original recipe, exotic metal and slow, deliberate hand assembly on a car built for volume was something no mainstream carmaker could afford to do a second time. If you're enjoying this walk through the engines that time is quietly leaving behind, take a second to subscribe. Every week I go deep on one machine and what its design says about the moment it came from. While all of this was happening out on the road, the rules underneath the whole industry were being rewritten, and the five engines still to come felt that pressure the hardest. Number 5. The Nissan RB26DETT. The heart of the car they nicknamed Godzilla. This 2.6-liter twin-turbocharged straight-six powered the Skyline GTR through the R32, R33, and R34 generations from 1989 to 2002, and it was never really designed as a street engine at all. Nissan built it around a racing brief to homologate the GTR for Group A competition, which is why the block is cast iron with a closed deck design that resists flexing under boost. Paired with a clever all-wheel drive system that could send power to whichever wheel needed it, the R32 went on to win touring car championships so completely, including a dominant run in Australia, that the Australian press handed the car its Godzilla nickname. On the road, Nissan quoted the same 276 horsepower everyone else did. On a dyno, standard cars regularly showed well over 320. Serious racers could order strengthened N1 blocks straight from the factory, built to survive endurance racing and long, punishing laps of the Nürburgring. All of that overengineering looked excessive in 1990, and it's the reason 30-year-old GTR cars still make monster power today. They're iron blocks shrugging off boost figures that would have seemed reckless when the cars were new. But an engine conceived for a racing formula that no longer exists, in a body Nissan stopped building decades ago, was never going to survive the move to smaller, cleaner V6s. When the GTR name did return, it came back with a different engine entirely, and the great inline-six was left behind. 4. The Toyota 2 JZGTE Toyota came at the same idea from pure ambition, and pushed it even further. Its 3.0-liter twin-turbo straight-six sat in the fourth-generation Supra and in the quieter Aristo luxury sedan, and it used a cast-iron closed-deck block fed by a pair of sequential turbochargers – a small one spooling early, and a larger one taking over up high. Toyota engineered the bottom end with far more strength than the factory power ever asked for, and that single decision turned it into the most worshipped tuner engine on the planet. The block is so stout that builds pushing past 1,000 horsepower on the original internals are close to routine, and a few have gone beyond 1,200 without cracking it open. Drag racers and drifters the world over still reach for this engine first, three decades on, precisely because Toyota left so much strength on the table. That's headroom you only design in if you're quietly building for a future you can't yet see. Here's the detail that says the most about where the industry has gone since. When Toyota revived the Supra in 2019, it didn't build a new straight-six to honor the old one. It borrowed an engine from BMW. A heavy, overstrong iron inline-six of that size simply can't meet modern efficiency and emissions targets, so the very company that built the most legendary tuner engine of all time looked at the numbers and chose not to build another one. 3. The Mazda 13 BR-EW The rotary earns a second place here, because the twin-turbo version in the RX-7 might be the most loved rotary Mazda ever sold. It's a tiny thing, just 1.3 liters across two spinning rotors, breathed on by a sequential pair of Hitachi turbochargers, a small one for instant low-end response and a larger one that takes over higher up. In the FD generation RX-7, sold from 1992 to 2002, it made the familiar capped figure in a car that weighed almost nothing and turned in like a scalpel, and it became a movie and video game icon along the way. The poster on a whole generation's bedroom wall, as famous on a screen as it ever was on a road. Mazda kept the rotary idea alive after the RX-7 II, in the RX-8, whose engine finally bowed out in 2012. But the rotary's flaws are baked into how it works. Those apex seals wear down over time, it burns oil by design just to survive. And it runs hot and thirsty in a way emissions and fuel economy rules grew less and less willing to forgive. Mazda's own leadership later said plainly that they ended rotary production to meet tightening emissions standards. Years afterward the shape did return, but only as a small generator quietly charging the battery in an electric crossover, never again turning the wheels itself. For the engine Mazda built its entire identity around, being brought back as a battery charger is a strangely quiet kind of afterlife. Number 2. The Lexus One LRGUE, the V10 from the LFA, and the engine this whole video opened with. Lexus co-developed it with Yamaha, the company better known for pianos and motorcycles, and you can hear that partnership the instant it fires. It's a 4.8 liter V10 that revs to 9,000 RPM and makes 552 horsepower. But the figure that stops people is the one about speed. It could climb from idle to that red line in 6 tenths of a second, faster than a normal analog tachometer could physically move its needle, which is the reason Lexus fitted a digital screen in its place. Inside were titanium connecting rods and valves, 10 individual throttle bodies, and a dry sump oiling system, and the whole engine somehow weighed less than the ordinary V6 in a Camry. Yamaha tuned the exhaust to sing, a sound owners still describe in almost musical terms, closer to an orchestra winding up than an engine, the kind of noise people travel across countries just to stand near. Lexus spent the better part of a decade developing the car around it, at one point scrapping an early aluminum body to start over in carbon fiber, then built exactly 500 of these engines entirely by hand over two years at its Motomachi plant. Every one of them was assigned to a specific buyer through an application process before it was even built. The LFA was never really meant to earn a profit, it was built to prove Japan could make something the Europeans couldn't, then it was over. A bespoke, hand-assembled, screaming V10 built for a two-year run answers a question no finance department would ever sign off on today. Number 1. The Nissan VR38DETT. And the reason it sits at the very top isn't its horsepower, it's the hands. This 3.8-liter twin-turbo V6, built around a rigid closed-deck aluminum block, powered the R35GTR, and every single one was assembled by a lone master craftsman, a Takumi, working by himself in a climate-controlled cleanroom at Nissan's Yokohama plant. Only a handful of people ever earned that title. Each engine took around six hours, and when it was finished, the Takumi who built it fixed a small plaque to the front, engraved with his own name, a ritual Nissan borrowed from the engine builders at Mercedes AMG. Over 18 years, the engine grew from 480 horsepower to more than 570, and roughly 48,000 of them were signed and shipped to owners all over the world. For most of those owners, the plaque was a detail they would never see, buried deep under the intake plumbing, and that was somehow the point. The care went in whether or not anyone would ever look. Then, on August 26th, 2025, the very last R35 rolled off the line in Tochigi, a midnight purple car built for a customer in Japan, and the Takumi stopped building new ones. Nissan's chief executive Ivan Espinosa said it wasn't goodbye to the GT-R forever, that the name would return one day. Even if it does, the next one will almost certainly be electric or hybrid, and it won't be a V6 signed by the person who spent a career learning to build it. Everything in this video comes from the complete manual, all six progression ladders, exact standards for every step, and three full programs. It's linked in the description, and the code NOEXCUSES, one word, gets you $20 off this week. So here's the question worth sitting with as this era quietly closes. When we say these engines will never be built again, we usually reach for the emissions rules, the cost, the electric future, and every one of those reasons is real and important. But the deeper loss might be simpler than any of that. It's the idea that an engine could carry a signature at all, that somewhere a person stood over it for six hours and then put their name on the work, and that a company thought we would care. No regulation took that away from us. We just stopped asking for it. If you want to see the cars these 10 engines actually powered, and where their value has quietly gone since, that story is waiting on screen right now.