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Toyota commissions Yamaha to develop hydrogen-fueled 5.0L V8; follow-on from Nov 2021 announcement

Toyota Motor Corporation has commissioned Yamaha Motor to develop a 5.0-liter V8 engine for automobiles that is fueled entirely by hydrogen. In Japan, Toyota and other automotive-related companies are about to begin a collaborative effort to expand the range of fuel options for internal combustion engines.

We are working toward achieving carbon neutrality by 2050. At the same time, ‘Motor’ is in our company name and we accordingly have a strong passion for and level of commitment to the internal combustion engine.

—Yamaha Motor president Yoshihiro Hidaka

In November 2021, the five companies of Kawasaki Heavy Industries, Subaru Corporation, Toyota Motor Corporation, Mazda Motor Corporation, and Yamaha Motor jointly announced they would begin discussions for conducting collaborative research into possible avenues for expanding the range of fuel options for internal combustion engines in the quest for carbon neutrality. (Earlier post.)


November 2021 hydrogen engine prototype.

At the announcement venue, the V8 hydrogen engine shown above, which was developed by Yamaha for Toyota, was unveiled to the public. The unit is based on the 5.0-liter engine in the Lexus RC F luxury sport coupe, with modifications made to the injectors, cylinder heads, intake manifold, and more, and delivers up to 450 hp at 6,800 rpm and a maximum 540 N·m of torque of at 3,600 rpm. FEB36F6A-2CAF-409B-99EC-70A301F45B6D

Hydrogen engines house the potential to be carbon-neutral while keeping our passion for the internal combustion engine alive at the same time. Teaming up with companies with different corporate cultures and areas of expertise as well as growing the number of partners we have is how we want to lead the way into the future.

—Yamaha President Hidaka at the Nov 2021 venue

Hydrogen: not a stand-in for gasoline. Yamaha began developing a hydrogen engine for automobiles about five years ago. Takeshi Yamada from the Technical Research & Development Center’s Automotive Development Section is a member of the hydrogen engine development team and he began to sense the depth of potential in the powerplant as the project progressed.

I started to see that engines using only hydrogen for fuel actually had very fun, easy-to-use performance characteristics. Hydrogen engines have an innately friendly feel that makes them easy to use even without resorting to electronic driving aids. Everyone who came to test-drive the prototype car would start off somewhat skeptical, but emerged from the car with a big smile on their face at the end. As I watched this, I started to believe that there is actually enormous potential in the characteristics unique to hydrogen engines instead of simply treating it as a substitute for gasoline.

—Takeshi Yamada

Another thing that Yamada and the team value in the development process is Kanno Seino, meaning sensual or exhilarating performance. One example is the harmonic high-frequency exhaust note produced by the engine’s 8-into-1 exhaust manifold.

This is a challenge we can sink our teeth into as engineers and I personally want to pursue not just performance but also a new allure for the internal combustion engine that the world has yet to see.

—Takeshi Yamada

Earlier this month, Yamaha announced it will bolster its research and development facilities for powertrain technologies aimed at achieving carbon neutrality, such as electric motors and hydrogen engines, throughout the duration of its new Medium-Term Management Plan (2022–2024).

This expansion will install in stages various new equipment, including electric motor test benches, hydrogen supply equipment, and carbon-neutral fuel storage tanks at Building No. 32, which was completed at the company’s headquarters last year. Once finished, the facility will play a leading role in implementing green technology measures for Yamaha products across the board.

In July 2021, the Company reviewed the Yamaha Motor Group Environmental Plan 2050 originally formulated in 2018 and set a new goal of aiming for carbon neutrality throughout all of its business activities—including across the life cycles of its products—by 2050.

Among these changes, Yamaha Motor set a goal of reducing Scope 3 CO2 emissions (emissions produced from the company’s value chain, e.g., use of sold products) by 90% by 2050 compared to 2010. This expansion of R&D facilities will further strengthen the development of new energy systems as well as accelerate their implementation.



What an undescribable pure waste of energy, time, effort, efficiency and financial resources.


Toyota's WTF development of the month. But it make cool noise and kept the engineers entertained. Personally, I prefer the lack of noise from BEVs and would rather see the engineers doing something more useful.

Hydrogen ICEs might make some sense if there was a low cost supply of clean hydrogen but, at the moment, it does not exist. The best possibility for reasonable cost clean hydrogen is high temperature thermal chemical reactions using Gen 4 high temperature nuclear reactors. However, Japan shut down most of their existing nuclear reactors so they can not even do high electrolysis. Even if you had a low cost source of clean hydrogen, fuel cells are more efficient although they probably cost more. Also, even if we had reasonable cost hydrogen, the first use should be to replace the steam reformed hydrogen that is currently used in industrial chemicals.


Mechanical Engineers couldn't design anything even close to this.
So they just keep on doing what they learned decades ago designing cool "stone age" contraptions.

Nick Lyons

Carbon-neutral synthetic fuels make a lot more sense if you want to continue with internal combustion engines. Make a gasoline or diesel drop-in replacement that uses existing fueling infrastructure. Of course that doesn't require you to make cool new engines.


Not much has been done to develop H2 ICE engines even tho at 33 kWh/kg H2 is 2-3 times more dense than gasoline. Perhaps some good will come of this research. An H2 ICE maybe be the ticket for a serial hybrid aircraft of the future or a replacement clean fuel for ICE cargo ships. I don't see it useful for ground transportation devices.

With intake manifold on the outside, and exhaust manifold on the inside of the V, that motor only makes sense as a speed boat motor. It is too high profile to fit under the hood of a land transport vehicle and even if you did (truck) the rest of the exhaust plumbing would be nightmarish.

A boat is also the only vehicle that could carry enough fuel to power a 450 hp motor motor more than very short distances between refueling.

H2 is gravimetrically more energy dense than gasoline, but much worse volumetrically.

This is an engineers implementation of a fantasy that will appeal to fans of Ed "Big Daddy" Roth‘s illustrations.

Those old codgers who trailer their lovingly maintained or restored classics to “Cruisin the Coast” on the Mississippi Gulf Coast every year to slowly drive by other old codgers slouched in beach chairs along the roadside who cheer the occasional massive burnout made possible by applying the front brake line locks.

Fun times, fun times.

Well, at least they will be able to turn their beach chairs around and watch this new fangled technology cruise by on the water without choking on the raw hydrocarbons flowing unrestricted from those muscle car and rat rod exhoust pipes. That’s bad for the COPD.


The oil companies will like this for there next grift, H2 fuel where not needed. With all the Co2 emissions to produce the H2 fuel, will the H2 ICE car even be lower emissions than an ICE car (well to wheels).


Inside-the-V exhausts are used on diesels these days; it reduces the amount of plumbing required between the head and a single turbocharger.  Of course, they don't use outlandish tuned manifolds like the one shown.


Engineer-Poet’s comment about “inside-the-Vee” exhausts is a good point,i.e. reducing distance to the turbocharger. The latest Ferrari 296 GTB and the McLaren Artura both have inside-the-Vee exhausts for their turbo v-6 engines, which brings up another point - why a naturally aspirated v-8?
Liebherr working with Mahle and JCB from the UK are working on H2 ICE and they both have turbos. Of course, these are based on their diesel designs and would be used in off road applications. So what is the purpose of this R&D other than helping Yamaha find work for their combustion engineers since the rest are probably working on electric motorbikes.


Cast exhaust equalizes temperature between the banks


SJC, if you don't know what a non-sequitur is, just be quiet.


EP the lunatic insulter


Talk sense to a fool, and he calls you foolish.

Roger Pham

If this H2 engine can develop 450 hp on H2 fuel without melting, it would be a great accomplishment, because H2 burns hotter than gasoline. I suppose direct injection and generous H2 fuel enrichment would be necessary to put out this kind of power!

What H2 engine really shine is high-efficiency and low emission at mid to low power range, when H2 's very rapid combustion permits very high EGR ratio and still burns rapid and complete enough to permit higher efficiency and lower emission than comparable gasoline engines. Toyota's gasoline engine now is capable of 41% thermal efficiency, and with H2 combustion characteristic permitting high EGR for high thermal dilution hence lower heat loss and lower pumping loss at part-load, ...can achieve 45-50% efficiency?...Almost on par with FC? Don't write off H2-ICE just yet!!!


You're so right Roger and at those high temperatures H2 combustion produces immense amounts of NOx. That is counter productive to current methods to reduce environmental pollution.


Hydrogen certainly has its justification as a rocket propellant or as a chemical component in some other chemistries but not as a propellant for mobility via land, air, or sea. It is, however, unbeatable as a fuel for aneutronic fusion. What development potential does H2 have? None! H2-ICEs underline the peak of stupidity. Life is difficult, “it is the most difficult of all” especially for the stupid.
Solid state batteries document the SOA. Quantumscape has the lead worldwide not only in their anodeless battery chemistry but in their specific technological platform as well. Once the transition “from lab to fab” has succeeded, there surely is still potential for further improvement. As far as battery development is concerned, we’ve experienced an unparalleled surge in a relatively short period of time. There is a long road of technical potential ahead of us before we reach its end. That definitely cannot be said for H2.

Roger, where do you see the capability (plumbing) for direct injection in this engine?

I see a notch on the top of the intake ports, which would indicate an injector mounted on the manifold, just ahead of the intake valve, a standard arrangement.

Better to see what this engine does have, rather than imagine what it might have, but does not.

It would be very unconventional to mount fuel injectors on the inside of the V next to the exhaust manifold, but variations of the UR family V8 this engine is based on came with conventional manifold injection, direct injection and both manifold and direct injection.

I don’t see any plumbing for direct injection, and running fuel, even gaseous hydrogen, alongside those exhaust pipes would be extremely problematic. It’s not impossible that this engine has direct injection in addition to the manifold injection we see slots for.

I’ll give Roger credit for having a better imagination than mine.

Roger Pham

I'm glad to see a live discussion here. Direct injection of H2 is a MUST in order to achieve 450 hp out of this engine without turbocharging or supercharging. Direct injectors usually are mounted on the side of the intake ports, and although not visible here, doesn't mean that they don't exist.
Yoatmon's comment regarding NOx is a moot point, because combustion temperature must be tempered down to make the engine viable, and the use of existing excellent reduction catalytic converter capable of reducing NOx level to legal limit.

What no one commented on is the presence of the alternator and accessory belt, serving also the A/C compressor, power-steering pump, and water pump...etc...What are they doing here in this H2 engine? The only way that a H2 engine is going to be viable in a vehicle demands that the vehicle be a Hybrid, a FULL Hybrid Electric, in order to have adequate range on the limited H2 storage available. An engine designed for HEV would NOT have an alternator, nor accessory belt, because all accessories will be electric.
What this means is that this is just a picture of a generic existing gasoline Lexus V-8 engine for the purpose of illustration only, and NOT meant to be placed in a H2 vehicle.


I've been looking at the sulfur-iodine process for thermochemical separation of water, and I realized that the use of hydrogen as a medium- to long-term (days to months) energy buffer fills a gap in the capabilities required to fully decarbonize energy supplies.  If we can get 52% heat-to-H2 efficiency in H2 generation and 50% in consumption, it's not too much worse than stored H2 run through CCGTs to charge batteries and the downtime for refills is less than charging.  Aside from the thermochemical stuff, the technology is already here and no scarce or precious materials are required.

Aside from the thermochemical plant (which i figure may cost about $1.00/kgH2 while amortizing and about $0.25/kgH2 afterward on top of the heat input) we'd need nuclear reactors running at about 1000°C.  We've already gotten close to this, so it has to be considered within reach.

Thomas Pedersen

What's up with these Japanese companies. Are they crazy or what?!?

I believe a central part of the reason is that Japan (and South Korea) has a national strategy to source energy by importing hydrogen (e.g. from Australia) and distributing the hydrogen as an energy carrier. The reason is that it is very difficult to create enough renewable energy due to geographic constraints. And they seem to be less in favor of nuclear

If you already have the hydrogen, is it then better to create electricity very efficiently at central plants and charge batteries, or to charge hydrogen and convert to rotational mechanical energy within the vehicle? My sense is that it certainly becomes feasible to have hydrogen vehicles, when the energy 'starts' as hydrogen.


This Yamaha Hydrogen engine is very intriguing!
Not only are the exhausts in the Vee but they are also 8 into one. The engine is based on the Toyota 2UR-GSE v-8 used in the Lexus IS-F and RC-F, this engine has both Port and Direct Fuel Injection, Variable Valve Actuation, and combined Atkinson/Otto Cycles. The Hydrogen engine also has almost the same power as the gasoline engine - 450hp.
Not much else is known. Definitely a design exercise (it might fit in a race car, not a front engine car like the Lexus IS-F). Many questions: Are the exhausts used for scavenging purposes? Does the Port Injection add a dilute H2 or water injection for cooling purposes? What is the thermal efficiency? Hybrid Application?
Yamaha is a R&D company (originally developed the 2UR-GSE) and are also into electric motor design, e.g. the Hyper EV electric motor in the Subaru STI E-RA EV.
Additional information would be interesting.

It’s very unlikely tho engine would be used in any land based Motorsport application.

ICEs are not efficient enough to be practical in small vehicles.

Consider that if a Toyota Mirai used an H2 ICE instead of a fuel cell, its three H2 tanks would need to be twice as large for the same range.

The Mirai is a mild performer, to be kind. Now consider how big the tanks would need to be to feed a 450hp engine operated at wide open throttle for much of its duty cycle.

“We’re gonna to need a bigger boat…”

Roger Pham

Agree with E-P's assessment about using nuclear energy for transportation. It seems that molten-salt Thorum reactors are most promising, safe, and very abundant source of energy to complement Renewable Energy. Countries that are low in RE potential like Japan, Korea, and Western Europe should invest heavily in new nuclear energy techs in order to become energy independent. We can make PHEV's instead of BEV's, that requires only 1/5-1/8 the battery capacity of a long-range BEV, and use grid electricity to drive in Springs and Falls when power consumption is low, while use H2 to drive in Summers and Winters when power consumption is high.

If you already have H2, then why not use it directly on board vehicles instead of using power plants to make electricity and use it to charge batteries. This is because Summers and Winters have the Electricity Grid heavily utilized, and if adding more power consumption to charge BEV's will need expensive Grid upgrade, PLUS massive investments in battery-making plants to the tune of $5 Billion USD per GigaFactory to make 500,000 BEV's per year. Why not make PHEV's instead, that requires only 1/5-1/8 the battery capacity of a long-range BEV, and use grid electricity to drive in Springs and Falls when power consumption is low, while use H2 to drive in Summers and Winters when power consumption is high?

Yes, port injection with water at high engine load can be used to reduce combustion temperature to lower NOx emission and to ensure engine durability, and to avoid fuel enrichment to improve fuel efficiency at high load. The water can be obtained from condensing exhaust gas, which contains high water vapor concentration, being the sole end product of combustion. One can look at water injection as another method of EGR, and in liquid form, permits full-volume Oxygen intake to permit maximum power WITHOUT fuel enrichment, as well as raising maximum power output due to evaporative cooling of intake air, as well as washing the intake valve from the carbon built-up from the gaseous EGR process and PCV process.

Why not use this engine in land-based Motorsport application? Motorsport carries only the driver and zero luggage space, thus plenty of space for fuel. Why not use Liquid H2, that is much lighter than petroleum fuel or methanol, thus permitting even better performance? The larger fuel tank size to carry H2 is of no problem in Motorsport.
Remember that BEV's have WORSE problem than H2-vehicles with energy storage density, BOTH volumetric and gravimetric wise.
Remember that the H2-ICE can have water injection for high-load cooling instead of using very rich fuel mixture in racing engines, thus making it more efficiency at racing power regimes when compared to gasoline or methanol racing engines.
Remember that Toyota gasoline engines are now capable of 41% thermal efficiency, with Toyota H2-ICE to be capable of nearly 50% thermal efficiency, which should stretch the fuel supply pretty far in comparison to previous gasoline racing engines.

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