It’s often hard to perceive moments in your life until they’re in your rearview mirror. The last time you and your childhood friends rode bicycles around your neighborhood. The last time you made a mixtape. The last time you went to your favorite college bar. The last year combustion-powered cars dominated the new car marketplace is another key moment only viewable in hindsight, and BMW thinks that’s already happened.
Yeah, that tracks. Reuters reports that BMW believes the peak of the combustion car has come and gone, at least in the Bavarian brand’s case. If anything, it lines up well with the direction of BMW, which is currently working on its Neue Klasse next-generation EVs.
Speaking to a media roundtable, BMW’s Chief Financial Officer reportedly didn’t mince words, painting a picture of how current and future business growth leans heavily on electric and electrified vehicles.
“The tipping point for the combustion engine is already there,” CFO Walter Mertl said, adding that in his view it had been passed last year.
“The current sales plateau for combustion cars will continue and then fall slightly,” he predicted, pointing to looming environmental regulation that will restrict sales of such vehicles.
Given legislation in Europe, Canada, California, and many other jurisdictions targeting an electrified vehicle mix by 2035, it’s not surprising that total mix of combustion-powered cars is expected to decline over the next decade. However, to hear that it was passed just last year is surprising. As it stands in the modern era, the mix of new combustion-powered cars sold has never been lower, with popular electric vehicles still gaining market share, even with the adoption curve flattening out as the most eager consumers likely already own EVs.
Granted, BMW has been on somewhat of an electrified tear over the past few years. Sure, the brand previously offered the i3 electric city car and i8 plug-in hybrid coupe, but its battery-augmented or battery-powered lineup is stronger than ever. The i4 (pictured above) holds mass appeal in that it’s largely conventional, while the i5 electric midsize sedan and i7 electric flagship sedan round out a three-car EV lineup in North America. China gets a new i3 EV based on the current 3 Series, but China also has a high EV mix, so that isn’t too surprising.
On the jacked-up side of things, BMW sells just one battery electric crossover in America, the iX. However, the brand also sells the iX1 subcompact and iX3 compact electric crossovers in the rest of the world, and an iX2 is coming as well.
Oh, and that’s before we get into plug-in hybrid models. Americans have four to choose from — the 330e, the X5 xDrive50e (pictured above), the 750e xDrive, and the XM — and that’s just a small slice of what the rest of the world gets. For example, in Europe, the current 5 series alone has several plug-in hybrid options before we even get into the upcoming M5 or the rumored M560e xDrive. Then there’s Mini with the Cooper SE and Countryman plug-in hybrid, and Rolls-Royce with the Spectre, both brands owned by BMW. It’s safe to say that the roundel is going hard in the paint on electrification, so this claim of being past the peak of combustion-powered cars makes sense.
If you haven’t been paying close attention, this proliferation of electrification throughout the BMW lineup may come as quite the shock. Historically, BMW’s been known for its silky-smooth inline-sixes. The company’s combustion engine prowess is literally in the company’s name, Bayerische Motoren Werke — where the middle word, Motoren, is German for engine. I quite literally bought into the hype and found the company’s engine-building reputation completely and utterly warranted.
However, we are nearly a decade past the end of production of the N52, the last naturally-aspirated inline-six BMW sold globally. As it stands, the BMW of today isn’t the same company it was when it made the rear-wheel-drive 1 Series hatchback, never mind the iconic 2002 sports sedan. It’s time to acknowledge that the future of the car is likely electrified, but that doesn’t mean we can’t revere the past. Let’s look back at five truly legendary engines from BMW.
M30
Available in just about every midsize and large BMW from 1968 to 1995, the M30 was an overbuilt juggernaut of an inline-six. It started life as a 2.8-liter or 2.5-liter inline-six, and eventually morphed into a 3.5-liter unit making 208 horsepower, gaining fuel injection, displacement, and a fearsome reputation for solidity along the way. If you wanted to go really fast, a variety of tuners like Dinan could add forced induction, and the motor held up at power levels rivaling some of the greatest exotic machines of the time. Even today, the M30 is revered for how it responds to boost, and how well it holds up both modified and in stock form. It’s simply a great engine, no matter how you choose to enjoy it.
S70/2
When Gordon Murray needed an engine for the greatest supercar of the 1990s, he initially turned to Honda. Honda said no, which sent McLaren running into the arms of BMW. Taking the bore spacing and block design principles of the S70B56 found in the 850CSi and adding heads derived from the European E36 M3’s S50B30, the S70/2 used variable valve timing, individual throttle bodies and the might of twelve cylinders to make 618 naturally-aspirated horsepower in 1992. It was good enough, along with a bit of rev limiter trickery, to help the McLaren F1 become the fastest naturally-aspirated production road car in the world, a record that stands to this day. If any BMW engine wholeheartedly deserves a spot in the pantheon of greats, it’s this one.
S54B32
The S54B32, found in the early-aughts BMW M3, the Z4 M, and later Z3 Ms, wasn’t the world’s most reliable engine. However, it was one hell of a technological feat. In European trim, we’re talking about a 3.2-liter naturally-aspirated straight-six good for 105 horsepower per liter, ripping to a redline of 8,000 rpm. It’s visceral, raw, and barely detuned for the American market. After years of a so-called second-rate M3, the U.S.-spec E46 M3 was a giant killer, the absolute performance zenith of BMW’s naturally-aspirated inline-six legacy.
N52B30
Shortly after the turn of the millennium, BMW started work on a replacement to its widespread M54 inline-six, and the engineers in Munich weren’t about half-measures. For this new engine, BMW used an open-deck block with aluminum cylinder walls and a magnesium casing, variable valve lift and timing, an electric water pump to minimize parasitic losses, and a three-stage valved intake manifold to optimize power and efficiency. The result? A full 30 more horsepower than the outgoing M54B30, in the same displacement, in an engine 20 pounds lighter, and with superior efficiency. Best of all, reliability wasn’t sacrificed to achieve these gains. The N52B30 is incredibly durable, with many examples crossing the 300,000-mile mark. It’s also the last naturally-aspirated inline-six BMW sold in America, a triumphant end to a dynasty.
S85B50
The first bespoke M division engine, the S85B50 was an odd-fire 90-degree V10, which is an exceedingly weird thing because the ideal bank angle for a V10 is 72 degrees. Split crankpins, anyone? Regardless of fundamental strangeness, the S85B50 was BMW’s only production V10, and it was a belter making 500 horsepower at 7,750 rpm. Sweet baby Jesus, we have lift-off. This five-liter all-aluminum mezzo-soprano made the E60 M5 a 200 mph sedan once the top speed limiter was removed, and that’s a very cool thing indeed. Even with a propensity to eat rod bearings, we’re thankful for the S85B50 because V10s are rarified air, and this one is the rowdiest ever installed in a sedan.
B58B30
In the modern turbocharged era, BMW didn’t exactly have the smoothest start. The N54 inline-six was plagued by failure-prone and unbelievably expensive accessories, the N55 inline-six was particularly fiddly when it came to oiling, the N20 inline-four liked to eat timing components, and the N63 V8 was a disaster. However, BMW stuck with the idea, and eventually ended up with a turbocharged inline-six good enough for Toyota. The B58 packs a heavyweight punch, responds exceptionally well to tuning, and is utterly ubiquitous. You can find it under the hood of everything from the X7 SUV to the 2 Series coupe to the Toyota GR Supra 3.0. It’s the real deal, and it seems to hold up brilliantly to piling on the miles. At last, BMW is on form again.
(Photo credits: BMW)
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Wow, finally the article that forces me to use the login feature and wake up the account I made when Autopian first started.
Anyway
I agree with Daniel MacDonald about the M20, but more importantly:
no M57 diesel?
Sort of surprised not to see the M20 on here, arguably more than the M30 the predecessor to the fast revving small displacement but potent inline 6s that would follow: m50, m52, m54, N52.
This article made me a little wistful; BMW engines were just one great part of what once made their cars so desirable. Sadly I think BMW really missed a swing with their early EV/PHEVs by some combination of trying to hard to be different and cultivating this eco-concious “i” sub brand. The early i3 and i8 were cool in their way, and the i3 is really underrated as a daily driver city car. But Tesla proved upscale car buyers want something that looks the part-and BMW probably could’ve beat Tesla at their own game before it even existed if they’d made EV/PHEVs that appealed to their core audience rather than being an upmarket alternative to the Prius. Then compound this with basically letting the i3 rot on the vine with no updates and no new product to build on the brand until years after the i3 came out and whatever little halo car effect the i8 created had faded away.
As a 3 time BMW owner I would loved to see them seriously tackle the EV challenge with fun, practical cars that have soul and reward you for pushing them. If they hadn’t been so relentlessly squandering their brand identity the last decade I’d find it easier to get excited about seeing what they’ll do with EVs. Where is their equivalent to the Taycan? Arguably one of the best looking sports sedans of all time and an EV-a car so desirable that it makes even an EV skeptic want to drive one. This space should’ve easily been BMW’s-instead they made the iX. I’m hopeful about this Neue Klasse concept but to be honest not very optimistic-nothing about it seems coherent with the iX, which is seemingly their flagship EV product.
This list is longer than I’d have imagined.
This is a lovely list, but it should’ve started with the humble M10, a single overhead cam inline 4 that introduced BMW to fuel injection and turbocharging in the 2002 Tii and turbo, respectively.
Furthermore, it had a dual overhead cam variant, possibly BMW’s first (I can’t confirm it with a quick search), called the M12, that was used in Formula 1 and remains the most powerful F1 engine ever, pushing 1300bhp in qualifying trim. It propelled Piquet to his second championship win, which was also the first ever Diver’s Championship victory for a turbocharged engine.
They also used the M10’s block in the S14 that came out in the E30 M3.
The M10/12 was the testbed for all of the modern technology that makes this list tick, it’s the granddaddy of every BMW performance engine.
It still amazes me that all the highest-paid designers in Munich somehow managed to come together and make the 5-series look like a front-wheel-drive compact, and that none of the many people with eyes who signed off on this project had the good sense to bite their fingers off and banish them from Bavaria until the end of time. I cannot stress enough how badly this thing looks like a scaled-up CLA or A3.
I’m aware this was completely off-topic, but my physical reaction to the cover photo was just too strong to not voice.
Define ‘great’
One of the primary reasons I ended up with a high-mileage MRoadster is because it is an older one with the S52: less power, but much more likely to get to moon-mileage without grenading.
when young, I memorized hp figures of extreme (for the time) cars. Decades later, working with complex HVAC systems, I grok that the farther you push things, the more ways they find to fail. In some ways, I’m beginning to subscribe to ‘the model T was the apex of technology’
‘said’ whilst typing on a hand-held computer, mind 😉
Y’all forgot the M50. It’s just as tough as the M30, but with the added refinement and top-end of a DOHC head. Their iron blocks make them handle overheating and boost like champs, and I’ve had numerous M50’s with 300k+ miles on them without ever opening them up. The M50 non-Vanos is the ultimate unkillable engine, there is truly nothing you can do to one to kill it.
I had an E34 wagon with a very unhealthy M50nv that made like 80psi on two cylinders, and I still put a ton of miles on it and beat on it every day; it never stopped working. Another M50nv was in a car that I drove to 312k miles before rolling the car (with the engine running upside down for a bit). That engine ended up going into another car where I added another 30k fairly abusive miles to it, and it’s still alive to this day with something like 350k miles, 6 track days, 1 rollover accident, and daily limiter-bashing.
Still kick myself for not buying a ’90 525i sedan w/ that motor that I looked at a few years ago. Drove great and felt faster than the rated HP (including feeling a pinch faster than the M52 powered ’00 323i I bought instead) but it had no service history so I was nervous the guy was dumping a time bomb.. They only offered that non-VANOS m50 for like 5 years though which I assume is why they didn’t have it on here-granted the N52 didn’t have a long production run either…
Well the non-Vanos M50 was offered for an even shorter time actually, in the US it was 91-92 model year cars only, after that it switched to the M50tu (vanos) from 93-95, and then 96+ all the cars switched over to the M52 which is basically just an M50tu with OBDII and a better oil separator system.
Couldn’t you get the e34 5 series starting in ’88 or ’89 which came with the non-VANOS m50? Either way helps prove my point that as great as the non-VANOS m50 is, it was sadly extremely short lived and I can see why it was left off of this list. I do wonder if the VANOS problems are over stated-I had a ’00 323i (m52TU iirc) with 215K miles when I sold it and as far as I know none of the previous owners had worked on it and it didn’t require replacement during my 20K miles of ownership. Though I do think the more rev-happy slightly peakier characteristics of the non-vanos are more fun though less daily driver friendly.
No, those early 525i’s actually came with the M20, they only switched to the M50 in late 1990 for the 91 model year. Vanos problems are definitely overstated, as the engines still work just fine even with it all worn out.
The N55 is underrated in the years between ’14-16.
They had it figured out by then.
Agree w: Is Travis on the N55. Compared to the boosted N54 in my wagon, which went through coil packs like cocktail shrimp at a buffet, my N55 has been downright reliable (knocks wood).
Mine has been completely flawless for the 45k miles I’ve put on my 335ix GT. I’ve done all the work on it myself, even made the mistake of forgetting dialectric grease on an ignition coil or two which was a full week headache.
Outside of the OFHG which you pretty much know going in, and the plastic charge pipe, they’re right in that sweet spot of notorious reputation equaling depreciation plus older German anything. It was the most bang for the buck I could get mid pandemic when I was shopping for something sub $20k that had the scoot, awd, room for the incoming family/kids, etc, and BMW 3 series with the N55 was it.
I did my research and budgeted $5k more when I started reading up on the N54 and earlier N55 and realized why those were going for $15k or less. Worth it for less headache as a DIY mechanic.
No flat twin??
No M10 4 cylinder?
So if BMW is done with internal combustion what does that leave them with?
Hideous grills?
Also Lexus.
I’d like to add the M54B30 to that list. It’s tough as nails, torquey thanks to it’s over square design and fuel efficient for what it gives you.
I wouldn’t daily a Z4M but my 3.0i is a joy everyday.
They are all perfect in their own way. Blessed are the Roundel, because they will be called Engines of God. May your valve cover gasket leak for all eternity. In nomine patris et filli spiritus Vanos.
Have any of y’all driven a BMW with the S58 yet? It might be my new favorite BMW engine. It’s an absolute monster, and all indications point to it being reliable as well, so… extra bonus.
I have not but I’m tempted by a certified X3M. I see them pop up in the high 40s pretty frequently and it’s a ridiculous amount of car for that price. I’m one of the weirdos who actually likes the current M2 as well.
Really my only beef with the S58 is the fuel economy. Don’t get me wrong-I’m not expecting anything super impressive with that much performance on tap, but low to mid teens city mileage is absolutely putrid for a 6 cylinder and would probably wind up being single digits in practice where I commute. This sounds cheesy but I’m not sure if I could live with myself if I was burning THAT much Dino juice and releasing the accompanying C02.
I’d love to take one for a rip sometime, but I think I’d ultimately rather have a B58 because it’s similar performance with dramatically better fuel economy. There’s also a part of me that would just rather have a V8 if I’m going to suck up miserable gas mileage.
The efficiency around town is BAD. I seem to average around 13 mpg, and at least in the M2, the fuel tank is pretty damn small to boot. Highway mileage isn’t awful, but that small tank obviously limits your range. I haven’t taken any road trips yet, but I’d guess that the range is no more than 250-ish miles.
So, yeah, the S58 isn’t perfect, but to me personally, the efficiency issue is far from being a deal-breaker.
Holy god, if they styled their upcoming cars after the Neue Klasse, but modernized, that would make me weak in the knees
If you want a premium EV and don’t want a Tesla for whatever reason the current BMWs are a great way to go if you can deal with the styling. They all have competitive range estimates, outside of the iX they’re built on normal ICE platforms so they largely feel like their gas counterparts that we know and love, and BMW has excellent lease deals on all of them.
As I’ve mentioned a few times my old man bought an X5 50E last summer and it’s an incredible car, although it’s a PHEV and not a full BEV. If I were to suddenly need a car (unlikely considering I got a bunch of preventative stuff done on the Kona N this weekend along with an alignment, thanks DC potholes) I’d strongly consider leasing an i5.
THAT BEING SAID…I worship at the altar of the B58. I’ve come across takes that it’s the peak of internal combustion…and while I’m not sure if I’d go that far (you can put your pitchforks away V8 Gang) it’s an absolute peach of an engine. It’s remarkably smooth, has more power than you could ever need, it sounds great, and it somehow gets better mileage than a lot of 4 poppers.
It’s also reliable…by German standards, which are subterranean, but still. If you want to buy a new or new-ish German car to keep long term a B58 paired with a ZF8 or manual is your best bet outside of spending 6 figures plus on a flat 6 Parsh. It also has huge tuning potential because of its beefy stock internals. You can just add a tune and be making 500ish horsepower in no time, if you’re into that sort of thing.
Hell if you want a track build specifically that might be as good of a way to go as a full M car to be honest. Anyway…all hail the B58. It’s correctly rated. Go drive one if you haven’t. It’s a treat.
While I’ve never worked on one, everything I’ve read about them suggests that the last two generations of BMWs are very easy to tune for more power with a programmer. You’ll basically get an inverse relationship between power and longevity, but gaining an extra 150-200 horsepower requires surprisingly little work.
Can concur, @Toecutter! I traded miles for smiles with a tuned N54. Later I6t designs have addressed many of the N54’s issues, so the B58 likely offers the best balance of power and reliability for a bmw turbo 6.
100% Co-sign. I picked up an ’18 440 off lease return a few years ago with the intention that it would be my last ICE transportation vehicle (I do truck stuff for work).
Silky smooth operation, not obnoxiously noisy, plenty of zip even before the basic Dinan piggyback tune that tacked on 40 instant HP and a better throttle response, absolute joy to drive in the twisties and still 26+ MPG when I’m not driving like an asshole.
Eventually I’ll be looking into a PHEV or BEV, but I hope I can keep the B58 going for many more years…
I wouldn’t exactly call Tesla a premium EV, although I guess people generally consider Teslas to have more cachet and series S is technically a luxury car. I agree with the rest of your take, however.
The best thing about the i4 is that it barely has a price premium to comparable ICE options, and it is by far the most premium EV in the price bracket. If I had the budget for a new EV, it would be a serious contender despite the fact that I prefer hatches/wagons. If BMW released an i3 or i5 wagon I would probably lose my mind! Or if Volvo releases an actual electric V60 that isn’t $70k.
Oh I don’t think they’re premium either. Their interiors are like Scandinavian prison cells. But normies perceive them as premium/they’re considered the best electric option in a lot of cases.
One of my favorite things about our 330e is that it just looks like a normal 3 series. And we were still able to get the M-sport packages on the PHEV. BMW doesn’t really throw the fact that it’s electric or PHEV in your face, and yet they have a ton of electrified models to choose from. If you don’t notice the charge door or the “e” instead of an “i” on my 330, you wouldn’t know it’s the PHEV version of the 330.
It hasn’t been as efficient on battery usage as my Gen 1 Volt was, but it’s way more fun to drive. I liked the modes in my Volt a bit better, because you had easier control, but you can still force it to use the gas and electric the way you want it to with a combination of modes and the battery hold feature. There’s really very little compromise with the 330e. You can do 0-60 in 5 seconds in sport mode, use electric only for short trips, or use a hybrid mode for long trips. It far exceeds the highway EPA rating for me, and I get between 45-50 mpg cruising at 70 mph. It’s heavier than the 330i, so you do feel that in the handling, but I’ll take the trade-off to only fill it up with gas every 4-5 weeks. I do wish it had more like 40-50 miles of electric range, but even with just a bit over 20, it does a great job for all the short trips we make throughout the day.
Not really. Most automotive V10s are 90 degrees, because they generally derive from the same engine family as 90 degree V8s. The only exceptions I know of are the Carrera GT and LFA’s engines, each of which is expensive and bespoke enough not to be related to another production engine.
“Best of all, reliability wasn’t sacrificed”
“open-deck block with aluminum cylinder walls and a magnesium casing, variable valve lift and timing, an electric water pump to minimize parasitic losses, and a three-stage valved intake manifold”
Open deck, aluminum cylinder walls, VVT, electric water pump, and extra intake manifold valves are all sacrifices in reliability.
I think you’re confusing reliability with mechanical simplicity. Though complex systems are inherently more prone to failure, the application of any technology is what matters. As a one time BMW mechanic, and verifiable M30 addict, I can tell you that the N52 is every bit as reliable as an M30, albeit more complex. I think we can see great proof of this in the miserable depreciation of these engines. If you ever want to know what engines last a long time, look for the ones that are in low demand.
Yes and no. I realize that mechanical complexity is not the same as reliability, but additional mechanical complexity will never impact reliability positively.
The main thing here is durability, eg. how well the engine will stand up to abuse. Aluminum cylinder walls will never stand up to excessive heat, rpm, and oil starvation like iron ones will, and the best engineered cam phaser in the world is still going to get ruined by dirt or sludge in the oil, and an open deck block is just not as strong. All of these are compromised, and they may be good compromises, but they definitely are compromises. Like everything is in engineering.
Then there’s things like an electric water pump that can’t not be less reliable. I can’t imagine it breaks less than a mechanical water pump(basically never), and it adds several failure modes.
Longevity, reliability, durability, complexity, are all different but closely related things.
i dunno. I bought my E90 330i with 60K miles on it and drove it past 225K. There were issues with the car – mostly involving oil leaks from valve cover, oil filter housing, and oil pan. (BMW does so much so well, you’d think they could figure out gaskets.) I did have to replace the water pump at 60K, but the replacement was still in there working well at 200K when I swapped it out just to make sure my daughter wouldn’t get stuck somewhere with it. The engine itself never missed a beat for all those miles. I even only had to replace the battery once. I’d still have the car if it hadn’t been for a series of torrential downpours and a clogged sunroof drain that flooded the car and screwed up the electronics. I get the idea that complexity in general leads to poor reliability and BMW has been as guilty as any manufacturer in putting out complicated engines that fail in all sorts of expensive and terrible ways. The N52 is not one of them.
“Then there’s things like an electric water pump that can’t not be less reliable. I can’t imagine it breaks less than a mechanical water pump(basically never), and it adds several failure modes.”
I can see a few advantages of electric coolant pumps. Firstly they can be shut off completely while the engine is warming up. This can eliminate the need for a thermostat while saving energy. Then once the engine is warm they can vary their speed just enough to meet the cooling demands, also saving energy. Doubling the pump speed requires eight times as much energy so a coolant pump sucks up 64x the power when the engine is turning at 2000 RPM as it does running at a 500 rpm idle regardless of the needs of the cooling system.
Conversely halving the pump’s speed drops the energy needed to 12.5% as much so its definitely worth moving that cooling fluid just enough to do the job and no more. It’s a lot easier to vary an electrical pump than a mechanical one*.
Finally an electric pump can be located anywhere in the cooling system, hypothetically even in the radiator. This – again hypothetically – could greatly increase flexibility of design, parts standardization and lower costs while also easing maintainence accessibility. Designers can also add smaller HVAC and battery system dedicated pumps if desired.
I wouldn’t expect an electrical pump to fail any more often than a mechanical one. In my experience failures tend to be broken belts, leaks, corrosion and wear. The first is eliminated entirely, the rest are unaffected but might be easier to fix when they do go out since the pump can be put in a more accessible location.
All this is also true for other pumps such as A/C compressors, power steering, etc. I think there are good gains to be had in going electric.
*BTW if you have a swimming pool and don’t already have one put a variable speed pump motor at the top of your shopping list. When I did the math the payback was about a year.
if you read more closely you might see where i wrote “these may be good compromises, but they are compromises”.
I think an electric water pump has several advantages, and the sacrifice in complexity and reliability is probably worth it depending on application, but it is a compromise.
I think an electric water pump is a water pump plus an electric motor. With all the failure modes and failure rates of a water pump, and the failure modes and failure rates of an electric motor. That’s what I mean by, “I don’t know how it could not break more”.
if you read more closely you might see where i wrote “these may be good compromises, but they are compromises”.
It was hard enough making it through the double negatives.
I think an electric water pump is a water pump plus an electric motor. With all the failure modes and failure rates of a water pump, and the failure modes and failure rates of an electric motor. That’s what I mean by, “I don’t know how it could not break more”.
Run that pump off a belt and you’ll find out.
Sorry for my writing, that’s how I talk too.
I’ve actually never had much of a belt issue ever, but electric motor issues are not rare. In the case of a serpentine belt, the belt only has to be better than the combined failure likelihood of an electric water pump, power steering pump, electric rad fan, electric AC compressor, perhaps electric vacuum pump, and however else you would drive the alternator, plus the likelihood of the whole electrical system, including relays, ECU, a million connections, and the battery.
Of course this is assuming the water pump is driven by the serpentine/fan belt. On my Honda it is driven by the timing belt, which better not have any issues. That belt is basically guaranteed for 100k miles until it is preventatively replaced
There’s no doubt in my mind that in general, a belt accessory drive will break less than a bunch of electric motors and associated controls, and an electric water pump is just a part of that.
“Sorry for my writing, that’s how I talk too.”
OK. I’ll figure it out 😉
“I’ve actually never had much of a belt issue ever”
I have. A few times. Those belts were turning the fan, generator and other things too. Belts slip, belts break, belts need to be replaced sometimes. So do idler pullys. I’ve seen those fail too.
I’m not as worried about electric motor reliability.. Electric cars have been using far more powerful motors under far greater stresses for a while now and as far as I know there haven’t been a rash of motor failures, at least without good reason. Compared to moving a car spinning a water pump is child’s play, especially if it’s not going to get stomped on by the driver.
It might also improve the reliability of the pump itself. I can’t imagine living idle to redline is an easy one for a pump. Keeping that pump moving as slowly as is needed to maintain engine temp regardless of the engine speed sounds like a recipe for longevity. Same for the oil pump. Even more so if the oil pump starts moving the oil before the engine cranks and keeps it moving for a bit after shutdown in turbo engines.
It’s not that electric motors are necessarily unreliable or failure prone, it’s that they are generally not as tolerant of dirt, water, and general abuse, and they have a tendency to burn themselves up. This is for normal 12v motors like in fans. Of course belts and tensioners have failures, but my experience is that if you fix squeaky noises before they become an issue, they don’t become an issue.
You’re right, it seems like the wide rpm range a water pump experiences would be bad for it. But belt driven water pumps often last hundreds of thousands of miles. Would they last a million miles if they ran at a constant rpm? Maybe.
An electric oil pump has some advantages, and I think some cars have an auxiliary electric oil pump to feed the turbo after shutdown. I think dry sump systems also often use electric oil pumps. But for a daily driver car I would never want to depend on an electric oil pump. I don’t need a loose wire or a corroded terminal nuking an engine. Also, driving the oil pump from the cam or crank as usual makes sense, because the engine needs oil flow 100% of the time it’s running, and it needs more oil the higher the rpm.
I have seen fan and blower motors fail so yes while its rare it does happen. The failures tended to be things like resistor packs or relays more than the motor windings or bushings. I’ve also seen oil pumps fail when the shaft key sheared off, water pumps fail from corrosion, power steering pumps leak due to seal hardening, idler bearings fail, all kinds of things. As my cars have gotten more modern I find I’ve had to deal with such things less and less.
I still think small electric pump motors will be the beneficiaries of EVs. So much work has been going into building powerful, efficient motors that can last the lifetime of the car, it would behoove manufacturers to apply that tech to pumps and fans as well.
You do have a point about oil demand being in sync with RPM, however I dunno how that relationship tracks. Does an engine at 7000 rpm need 14x the flow as it does at an idle of 500 rpm or can it get by with three times as much? Maybe it needs less flow with cold oil as it does warm. More flow with old oil vs new, etc. Electric pumps can be smarter in how they meet oil demands. As to a failure causing engine damage the solution might simply be to have a cutoff should oil pressure be lost.
I think the amount of oil an engine “leaks” out of the bearings increases pretty linearly with rpm, but as rpm increases, cylinder pressure and power increases, so it needs more oil pressure and more oil flow. The rule of thumb is that an engine needs minimum 10psi of oil pressure per 1000rpm, so like 70psi at 7k.
An engine can totally get by with less oil flow when it’s thick and cold, but it’s also not bad for it to just build 50psi of oil pressure at idle when it’s thick and cold.
“As a one time BMW mechanic” I’d expect you to know the pitfalls of aluminum open blocks and especially of aluminum cylinders, it’s not like the sad story of nikasil/alusil failures is any kind of secret, or that their existence is due to one thing and one thing only: they’re cheaper to make than having proper liners.
When your engineering is taken over by penny-pinching, then your engineering is not much to be celebrated anymore. See also wet paper towel bearings, general ineptitude at keeping oil inside an engine (valve covers, oil filters and even damn valve seals)
I’m neck deep into a pair of E65 Alpina B7s at the moment, probably the poster child of BMW reliability issues in the 7 series. What’s interesting to me is that even with the extensive use of plastics, the cable routing, line path, and dedicated retention is miles ahead of what anyone else was doing in 2007.
I bring this up because I believe that there is a false conception about BMW’s willingness to invest in longevity extending designs. I don’t believe this to be the case. True, many modern BMWs have feature which I have no intention of living with, but they are also miles ahead of their rivals in powertrain development. From the vastly superior ‘reverse flow’ V8s, to the genuinely absurd B58, I think BMW is making some great stuff, even if it’s not to my tastes.
And as for the advanced block materials, the N52 is one of the best things BMW ever built, and that was compacted graphite/iron. I love being able to throw my M30s into a bucket of hot lye as much as the next guy, but we have to admit that aluminum blocks are here to stay, and any critique on the basis of not having iron wear surfaces is just silly. And per the wear resistance of Aluminum, remember that Aluminum oxide is what most sandpaper is made from.
Sure, all of that is great in theory.
In the real world they are continuously proven garbage (the Alu wear surfaces, not the Alu blocks, those are great for anything not boosted to the moon). In theory every single BMW owner always checks his oil at every tank fill, follows the service intervals religiously, only uses the right spec oil etc.
And no matter how advanced BMW engineering was at any point in time, when the “high tech” of valve seals or decent main bearings was a universally solved problem, including by BMW in previous decades.
The M54B30 is IMO one of the best gasoline ICE engines out there. Since BMW owns what remains of Triumph, this would make a great swap into a Triumph Spitfire or GT6. Neither car would gain an appreciable amount of weight, so the balance would remain, and you’d have increase fuel efficiency to go with enough horsepower to hit 0-60 mph in under 4 seconds, IF you can get enough traction(that would be very difficult).
A Spitfire or GT6 with this engine would twist into a pretzel in a few miles, if the swing arm suspension didn’t kill you first. It would be like the restomod equivalent of a TVR.
That is the idea!
You’d ned to reinforce the chassis with a roll cage for added stiffness, upgrade to disc brakes on all for wheels, upgrade the tires, swap out the transmission/driveshaft/differential/rear suspension…
But in the end, you’d have a car that was under 2,000 lbs and had over 300 horsepower, and could probably approach 40 mpg if not driven like a jackass.
At under 2000lbs and with over 300hp, I project many of us would absolutely drive it like a jackass. 🙂
Unless you are adding quite the turbo, no M54 is getting you close to 300hp. I completely support your idea but will strongly voice my vote for the N52 over the M54, based on experience with both in 3-series form.
My favorite candidate for 2000lbs and over 300hp is an MR2 Spyder with a 2GR V6 and matching manual transmission swapped in. The engine fits with just a little bit of hammer encouragement to the firewall, and the aftermarket community makes nearly all of the pieces(LSD as well) and tunes to get it well sorted and putting out 350hp while remaining reliable. Exhaust pieces need to be fabricated, and for track use it needs a big brake kit(and cage of course), but otherwise it’s about as plug-and-play as you can get with a swap.
I know about this conversion. It’s such a well-balanced and well-matched set of components. The best part is that the chassis can handle it.
I think you would have to step up to a TR6 to carry that engine. Or a Stag.
If I remember correctly, there is a hood clearance issue with the Spitfire/GT6. The TR6, on the other hand, will accommodate an M50 quite nicely. I expect that an N52 will drop right in as well.
If you can shoehorn in a M54B30 could you not cram in a cheaper, simpler, maybe lighter LS with even more power?
I saw a GT6 with an LS1 swap at a car show 2 years ago. The owner claimed 11 second 1/4 mile drag times, and 30 mpg driven locally on the highway without concern for the speed limit.
LS Is Always The Answer.