Time comes for all of us, and it comes for all engines, too. The Bentley W12 is the latest casualty of progress. The last engine has now been built, closing a chapter on two decades of production.
Bentley says the W12 was the most successful 12-cylinder engine of the modern era. It was certainly one of the most popular, with over 100,000 examples hand-built at Bentley’s Dream Factory in Crewe, England. It starred in roles across the company’s lineup, most notably propelling the Bentayga, Continental GT, and Flying Spur.
Bentley marked the occasion with a commemorative luncheon, as is the British way. The W12 teams gathered for a group photograph, and the engine assemblers were gifted W12 engine pistons as a lasting memento of the occasion.
The W12 came into being as an offshoot of the Volkswagen Group’s work on the VR6. This was essentially a V6 engine with a very narrow angle between the two cylinder banks. Instead of the usual 90-degree or 60-degree gap, the banks were split by just 15 degrees. This made the VR6 very compact and allowed both banks to share a single cylinder head.
The W12 was then created by simply sticking two VR6 engines together with a common crankshaft, split with a 72-degree angle between them. What do you get when you put two Vs together? You get a W, hence the name. Volkswagen first dropped it in a concept car, then the Audi A8 in 2001.
Bentley first debuted the engine in the 2003 Continental GT. The 6.0-liter W12 was given twin turbochargers which boosted its output to a mighty 552 horsepower and 479 pound-feet of torque. It pushed the Continental GT from zero to 60 mph in just 4.8 seconds, on to a top speed of 198 mph.
W12 engines are also commonly credited with passing the ‘coin test.’ It’s said that one can start and run the engine without disturbing a coin placed on its edge.
Development continued over the years, with the W12 gaining yet more power with each subsequent update. Bentley closed out production with 120 ‘Speed Edition 12’ examples of the Bentayga, Continental GT, and Flying Spur. These models put out 650 horsepower and 663 pound-feet of torque.
Notably, pedants for historical accuracy will contend that Volkswagen should have called the engine a WR12. The W12 designation was historically used for engines that were essentially three inline-fours combined around a single crankshaft. Examples include the Napier Lion and the former Life Racing Engine from the 1990 Formula 1 season.
It’s worth noting that the end of W12 production is actually overdue. It was originally slated to cease in April 2024. However, come May, Bentley was still at it, announcing that the limited-edition Batur and Batur Convertible would feature the engine. Just 18 coupes and 16 convertibles are to be built by hand. They will feature the most extreme examples of the W12 engine, boasting 740 horsepower and 738 pound-feet of torque. Based on today’s press release, it seems the engines have been finished, even if the cars are still under construction.
Now, it seems the curtain has finally closed, however. “It concludes a pivotal chapter in Bentley’s history, as the last W12-powered Bentayga, Continental GT and Flying Spur cars roll off the production line at the company’s Dream Factory,” read the company’s statement.
The W12 will be succeeded by Bentley’s new Ultra High Performance Hybrid drivetrain. It will combine a 4.0-liter twin-turbo V8 with an electric motor for a total output of 771 hp and 737 pound-feet of torque. It will also offer an all-electric range of up to 50 miles.
We were promised that the age of combustion was over, and that electric drive was the way forward. That hasn’t quite come to pass as we expected. Still, the biggest engines are leaving us, one by one. The Bentley block is just the latest of the big twelves to be put to bed. Vale.
Image credits: Bentley
I’m assuming it’s actually because the W12 is an overly complicated and heavy unreliable piece of shit that already had its main complimentary engine (the VR6) discontinued long ago and is over twenty years old now itself. It’s actually super compact for what it is, but the twin turbo Audi V8 was always the better engine.
When I worked for a german OEM, I often worked together with colleagues from Bentley, who did their testing in our facilities. I have to say: Wonderful people, always enjoyed working with them.
Drove a Bentley Conti GT with the TT version of that engine about 10 years ago. My God was it smooth. Its like they had Piech ride around in the back seat and every time he felt or heard ANYTHING, his butler would glove-slap the NVH guy.
What really should be talked about more is the ol’ 6 3/4 (6.75L) V8 that this engine essentially replaced. In its peak form it was twin turbo’d and put out 811 lb-ft of torque at 1750rpm! It is the longest running production engine ever (the modern Chevy Small block differs enough from the original to be considered the same engine).
https://www.topgear.com/car-news/british/11-things-you-need-know-about-bentleys-675-litre-v8
I guess you forgot about the air-cooled VW, made in mostly the same form from 1938-2003? I’m pretty sure there are several other automotive engines that were manufactured in some form longer than the Bentley’s 61 years, even if Top Gear says otherwise.
I’m just trying to wrap my head around the geometry here. If each pair of vees is at a 15 degree angle, why are the pairs separated by a 72 degree angle? I could maybe make a case for 60 degrees for balancing purposes, but am struggling to see the reason for choosing 72. Any engine wizards out there who can explain, or is this just VW doing VW things?
Those W engines are shitty even by VW standards
I wouldn’t call them any shittier than any normal v6 really. They tend to develop head gasket issues but I don’t think they are worse than for example a boxer engine.
Oh, yes they are! And they are VERY difficult to work on too!
google W8 timing chain for fun lol
The W12 timing chain is bad, but don’t pretend that that Audi V8 timing chain situation is any better.
Pretty sad that GM and Mopar pushrod V8s are making almost as much horsepower without forced induction. And with about 1/3 of the parts. And in a package that’s smaller and lighter. And way cheaper.
Those GM and Mopar pushrod V8s not only use fewer parts they are cheaper, more reliable, nicely growly AND they get better fuel economy.
You say sad, I say amazeballs!
You’re right, I meant sad for VAG. Have you seen the video where the guy tears down a W8? Its as if they designed it specifically to be as complicated as possible. Add another 50% complexity for the 12. Has there ever been clearer proof that “expensive for the sake of expensive” is stupid?
Hybrid drive is the way forward.
Less cylinders and increased lameness is definitely not the way forward.
If it’s the same 4.0TT (or an evo version as VAG does) they’ve been using since like 2013 in cars like the Urus, S8 and RS7, then there’s nothing lame about that mill, especially when it’s got help from a big honkin’ electric motor.
I’m so confused. If the newest Prius can get 50+ mpg city or highway, and still reach 60 within 7.2 seconds…that doesn’t sound lame to me.
And I love when my 2012 v switches to EV mode in town. Makes it nice and quiet. When there’s no one behind me and at least one other lane for people to pass me, I like accelerating below the level before the ICE turns on just for fun.
I don’t necessarily have any beef with hybrids, nor am I saying that they’re lame.
What is lame is McLaren downsizing from V8s to V6s, Bentley downsizing from W12s to V8s, Lamborghini downsizing from V10s and V12s to V8s, and Mercedes trying to put a four cylinder in everything.
Whether it’s hybrid or not, less cylinders is less cool. And on very high end performance cars, I just can’t think of any good reason why so many companies are doing this. If a small displacement engine is needed for emissions, I get that, but that doesn’t have to be lame. Small displacement engines with lots of cylinders can exist, and they’re awesome.
IMO the smart way to do a high end hybrid car is like the Porsche 918. A smallish V8 that’s naturally aspirated and revs to ludicrous rpm, but has poor low end torque, but that’s okay because the electric motors are there to help. No reason that a car with efficient and torquey electric motors needs to have an efficient and torquey but highly lame turbo V6(looking at you, Acura NSX).
Complexity for the mere sake of complexity is not very cool. Even in the dark days before hybrid assist I don’t think anyone considered the BMW M1 with an I6 less cool than say either a 4 or 8 cyl Lotus Espirit or a V12 Lamborghini Countach. All those wedges were well represented on many a teen’s wall.
The coolest of the lot you mentioned is the 4 cyl Lotus Esprit IMHO (although all of them were pinned up my wall).
Complexity for the sake of complexity is not cool. But that’s not why you want an engine with more cylinders(did you really think that all the V12 manufacturers were doing it just for style points?). More cylinders, all else being equal, allows for more rpm, more power, while simultaneously being significantly smoother and often delivering better low end torque.
In other words, a 12 cylinder engine performs better in every way than a 4 cylinder engine.
But more importantly, more cylinders means more fun. A V10 sounds better than a turbo four or a V6, every single time. And that’s what really matters if you’re buying a fancy sporty car in the Year of our Lord 2024. If you’re buying a McLaren, it’s not for the speed(because it’ll get outrun by a plaid Tesla every day of the week). It’s because you think that a combustion engine is more fun than that Tesla. But if it has a super lame turbo V6 just like every single F150, then it’s not doing a very good job of being more fun than a Tesla.
did you really think that all the V12 manufacturers were doing it just for style points?
Actually yes. To some cylinder count = bragging rights ESPECIALLY when all those extra cylinders do add is conspicuous cost and complexity.
As I mentioned earlier an I6 with its inherent primary and secondary balance is plenty smooth. Increasing cylinder count disrupts that until that count returns to a V12, which is just two I6s fused at the crank.
“More cylinders, all else being equal, allows for more rpm…”
I don’t think that’s necessarily true. F1 engines have varied between 4-12 cylinders and AFAIK none of those have had any problems achieving crazy high rev limits, especially once the valve springs were replaced with pneumatics.
“In other words, a 12 cylinder engine performs better in every way than a 4 cylinder engine.”
Not in packaging. Not in fuel economy. Not in weight. Not in cost. Those are performance metrics too.
If what you say was 100% V12s would be a LOT more common (albeit in much smaller displacements.)
“But more importantly, more cylinders means more fun. A V10 sounds better than a turbo four or a V6, every single time.”
IYHO of course. Beauty is in the ear of the beholder…or something like that. Lots of folks like an Audi I5, a VTEC I4 (yo!), a VR6 or a Busso. And weirdos get to vote too! Ask Torch and I’m sure you’ll get an enthusiastic vote for a wheezy, stuttering B4 with a bad miss.
Inline sixes do have perfect primary and secondary balance, and that is good, and I would not be mad if Mclaren replaced a V8 with a straight six.
But primary and secondary balance describe only the vibration that the engine produces; there are other factors in overall smoothness and NVH perception. Power pulse overlap is a good thing, and more cylinders means more overlap. This is why a V8 feels smoother and better than a Subaru boxer four, even though they both have perfect balance.
More cylinders allows for more RPM ***all else being equal***. You missed that part. A 3.0L V12 will outrev a 3.0L four cylinder, every single time. All of the things that limit RPM(valve float, flame front speed, piston and rod mass, piston speed) become less of an issue when you make the cylinders smaller. Yes, F1 has had high revving four and six cylinder engines. Obviously four cylinder engines can rev high(sportbikes exist after all). But big four cylinders cannot rev high. The only way to make a large displacement engine that can rev really high is with large numbers of cylinders.
Also worth noting that, for a given displacement, the engine with more cylinders will have significantly better throttle response. This is in a large part because more power pulse overlap allows for a lighter flywheel, to the point where a V12 typically doesn’t need a flywheel at all to stay running.
Would V12s be a LOT more common if they really were better? I would argue that through the 60s, 70s, 80s, and 90s, a very large proportion of cars whose price tag could support a V12, did have a V12. Used to be, just about every exotic car had 10-12 cylinders, and all the best luxury cars did too. It’s just that not many cars were expensive enough to justify the considerable price jump from 8 to 12 cylinders and the comparatively modest performance and smoothness improvement(more cylinders is better, but 8 is already a lot).
Obviously, there are reasons why every car doesn’t have, and shouldn’t have, a V12 or V16 or V24. And it’s not really that big a deal that this Bentley doesn’t have 12 cylinders any more, since the turbos and electric motors fully compensate for the slight disadvantages from dropping four cylinders. But, even for a luxury car that may not need ultimate high rpm performance, there are some unique smoothness advantages to lots of cylinders.
But what really is making me say all this is just because I’m a nerd who reads the Autopian, and so I will be extremely bored in 2060 when the only cars still legal to drive on the road have 2.0 turbos with eight speed autos, or a couple higher-performance cars that have 4.0 V8 turbos and eight speed autos. There are very good reasons for a few cars to have specialized engines, but those few manufacturers are ditching interesting, unique, and optimized engineering in favor of bland homogeny and quadruple dipping in the parts bin. I miss when we had Audi I5s and VW VR6s and the Ford big straight six and a Lincoln V12 and other such interesting machines. All of these were engines that made no sense for 97% of cars, but were very specifically optimized for the 3% that did.
“More cylinders allows for more RPM ***all else being equal***”
Maybe that’s true, maybe in theory a V12 can rev to infinity and beyond when an equivalently sized I4 or V6 can only rev to infinity. That is meaningless if the rest of the engine can’t keep up though.
Even so a large I4 can do just fine. Here’s a 4.4L 4 cyl that can rev to 10,500 RPM:
https://www.autoevolution.com/news/thor-v2-meet-the-inline-four-that-revs-to-10500-rpm-and-makes-up-to-3000-hp-218732.html
https://www.enginelabs.com/engine-tech/4-liter-4-cylinder-built-for-world-domination-meet-thor/
(That long block BTW weights only 233 lbs!)
So I’m pretty sure piston count isn’t going to be the rev limiting factor in a modern 4 cylinder 3L engine.
Maybe Bentley could use an engine like this one. It would be a return to their roots…blower:
https://en.m.wikipedia.org/wiki/Bentley_4%C2%BD_Litre
“I would argue that through the 60s, 70s, 80s, and 90s, a very large proportion of cars whose price tag could support a V12, did have a V12.”
…
“But, even for a luxury car that may not need ultimate high rpm performance, there are some unique smoothness advantages to lots of cylinders.”
I counter by pointing out that several luxury manufacturers who’s price tags and need for power and smoothness where weight is less of an issue did not have a V12 in that timeframe. No V12 from Lincoln, Cadillac, Lexus*, Infiniti, RR, even Bentley. V8s were fine even with displacements of up to 500ci.
*Toyota did in their Century so its even more curious why Lexus didn’t offer it in their flagship as well.
Cadillac and Lincoln didn’t offer a V12 during that timeframe, but Lincoln sold a V12 earlier, and Cadillac sold a V16 even earlier than that.
Of course a V8 worked just fine for smoothness and power, and I’m not saying it won’t for this Bentley or anything else. Eight cylinders is still a lot, and 90° of power pulse overlap(depending on the V8) is still great. But I still think the general trend of fewer-cylindered and more-generic engines is a Bad Thing™. This Bentley will still be smooth and powerful and fine and good with the Audi/VW/Porsche/Lamborghini V8, but it’s not as special or unique, it won’t be quite as optimized for its specific application, and it will definitely be a bit less smooth(from the engine itself, im sure they’ll compensate for this with looser motor mounts, a slushier transmission, and hybrid power).
That Thor 4 liter engine is extremely impressive, but we are talking about production street legal engines with the major caveat of *all else being equal*. Not sure why you think a single thing is equal between a production street engine and an all billet race motor so insane that they won’t even sell it to anybody who doesn’t already have a race team.
I don’t know why you don’t believe me that an engine won’t rev higher if it has smaller lighter rods, smaller lighter pistons, smaller lighter valves, lifters, and springs, a smaller faster combustion chamber, and a lighter, better balanced crank. You can get around any of these problems with liberal application of titanium, valve spring pressure, and race fuel, but that is obviously absurd in the context of our conversation.
“Lincoln sold a V12 earlier, and Cadillac sold a V16 even earlier than that.”
And then they stopped while gas was still cheap and emissions hypothetical because they found V8s were just fine.
“Not sure why you think…”
My point with Thor is to show a large, real world I4 can rev to the moon and put out more power than any sane person could ask for, that it’s not only possible, it exists.
“I don’t know why you don’t believe me that an engine won’t rev higher if it has smaller lighter rods, smaller lighter pistons, smaller lighter valves, lifters, and springs, a smaller faster combustion chamber, and a lighter, better balanced crank.”
I said it doesn’t matter a whit if the valve train can’t keep up. Valves are the limiting factor, not pistons. Also sometimes regulations.
Its also worth keeping in mind thermodynamic efficiency starts dropping past a sweet spot so high revs kill engine efficiency which IMO is the bigger cardinal sin. Maybe you’re OK with 6 mpg, I’m not.
But the valvetrains keeping up is WHY an engine with smaller pistons revs higher. Yes, it’s all about the valvetrains keeping up. And a 4.0L V12 has valves far smaller/lighter/faster than a 4.0L four cylinder. Meaning, for a given spring pressure, the V12 will be able to rev way higher before running into valve float.
“Maybe you’re OK with 6 mpg, I’m not.”
That’s fine, and great, and good. I’m not saying that you should drive a car that gets 6 mpg or has 12 cylinders, and I’m not saying that regular cars should have 12 cylinders. But you’re not a Bentley or Lamborghini buyer, and regular cars are not Bentleys or Lamborghinis. I am advocating for high cylinder count engines exclusively on cars for which the added cost of worse fuel economy and increased manufacturing cost are irrelevant. V12s only make sense on extremely high end cars.
I’m not saying that every Honda Civic in the world should have a V12. I’m saying that every Lamborghini in the world should have a V12.
Also worth noting that there is no “sweet spot” beyond which thermodynamic efficiency drops off; it’s very linear, less rpm is always better. That’s why the most efficient internal combustion engines are huge marine diesels that run on the order of 100rpm.
But the valvetrains keeping up is WHY an engine with smaller pistons revs higher.
I don’t think that’s true given the highest revving F1 engine today is a V6 at 20,000 rpm. Of course you can always conjoin two of those and declare victory with a V12 but then you have twice the headaches with no real benefit other than bragging rights.
“Also worth noting that there is no “sweet spot” beyond which thermodynamic efficiency drops off; it’s very linear, less rpm is always better. That’s why the most efficient internal combustion engines are huge marine diesels that run on the order of 100rpm.”
For a given engine it depends on the engine design, the fuel, etc. Most automotive and motorcycle ICE engines are pretty inefficient at lower rpms:
https://www.researchgate.net/figure/Thermal-Efficiency-Vs-Engine-Speed_fig1_322128091
(this 150 cc engine clearly shows an efficiency sweet spot at about 6000 rpm).
Big marine diesels are designed to turn slow to reduce the need for reduction gears since those giant props can only turn so fast and reduction gears sap power. Those massive engines are about 50% efficient which is the same as Mercedes tiny F1 1.6L V6 from a few years ago:
https://www.motorauthority.com/news/1112999_mercedes-amg-f1-engine-achieves-50-percent-thermal-efficiency
No cylinders, less complexity, and plenty of power is the way forward.
Or did you really think that the flying cars we were promised were going to be powered by a pushrod V8 operated via a manual transmission?
And backward with weight penalty and environmental impact, especially the battery pack. The new BMW M5 (G90) and Mercedes-AMG C 63 S (W206) are shockingly HEAVY due to the hybrid drive and battery pack.
They are already heavy WITHOUT the hybrid battery. That is the real problem with cars these days.
Ok, how come is W206 with tinny four-pot engine and hybrid drive 700 pounds heavier than W205 with non-hybrid V8 engine as well as G90 with hybrid drive 1,000 pounds heavier than F90 without one?
Your argument is pretty lame…
If you are trying to say that an engine plus one or more electric motors plus a sizable battery is always going to be heavier than a larger engine, then you are right.
But you are wrong in that the hybrid has actually less environmental impact (if used properly, that goes without saying).
“What do you get when you put two Vs together? You get a W, hence the name”
Well it’s not REALLY the shape of a ‘W’
It’s still more like a V, but a V where both top ends are split.
If it was truly a W engine, then you need to have to completely separate crankshafts and 3 separate cylinder heads… 2 outer cylinder heads with 3 cylinders each and a center cylinder head for 6 cylinders shared between two separate engine blocks.
I remember trying to wrap my ahead around it being “W” way back when. Thankfully I had already wrapped my head around why a VR6 is a V6, but still the whole W thing was a new one for me. I had been hearing of this engine for a long time. I think it realistically came about in the late 90s in several Bugatti Concept cars. Now, did it EXIST at that point, I personally do not know. Supercars.net was the start of my automotive, data, and technology obsession. I saved pictures of cars to floppy disks and shared them with friends. ha!
Don’t give VW any ideas, man….
You mean like making an actual W-engine, but make it a diesel with a timing chain in the front and in the back that should last for life but won’t because of cheap plastic chain guides? And use the same ‘wear item’ cam material as the V10 TDI? And make O2 sensor replacement an engine-out job? And install the starter at the back UNDER the middle part of the W… and putting exhaust pipes under it ensuring the starter motor gets cooked over time AND replacing it is also another engine-out job?
I’m sure VAG would NEVER put bad design ideas like that in production.
No sir… Nuh uh…
Good golly is the Batur a beautiful design.
The W12 always felt like a more exotic engine than a standard V12. For that reason, the Bentley and Audi vehicles with them felt more special. Ride into the sunset forever more, W12.
Piech’s last hold over