It’s not very often a rare trim of a car currently in showrooms can be considered a Holy Grail, but the current BMW 5-Series’ long production run gives it an unusual diamond in its crown. I’m talking about a 5-Series that, in the United States, will make a limited-production M5 CS look as common as a Ford F-150, since only around 100 examples made it to America. I’m talking about the 2018 BMW 540d xDrive, one of the last diesel BMWs sold in America and the only one of its kind.
First, a bit of background: A long, long time ago, Americans could buy brand new cars with BMW’s M21 diesel inline-six. Built as a response to the oil crisis of 1973, this strange 2.4-liter inline-six found its way under the hood of such varied vehicles as the BMW 524td, the Lincoln Continental Mark VII, and the Vixen 21 TD RV. It would be the last diesel BMW sold in America for two decades, partly because it imbued everything it came in with leisurely acceleration — the antithesis of BMW’s Ultimate Driving Machine image of the time.
Fast-forward to 2008, and the energy climate was very different from in the 1980s. With high fuel prices, increased environmental focus, and a burgeoning passion for U.S.-market diesels, the time was right for BMW to re-introduce diesel power to the American market. After refining its diesel-making prowess with the M51 inline-six, BMW unleashed the mother of all diesel hot rod motors on America in the 2009 335d and X5 35d – a little number called the M57B30.
This turbocharged three-liter juggernaut made just 35 fewer horsepower than the turbocharged N55 inline-six in the facelifted 335i, but it unleashed a 425 lb.-ft. torrent of torque at the rear tires of the E90 335d. If you could keep the obscene single-peg open-differential wheelspin at bay, the zero-to-60 mph dash was dispatched with in under six seconds, all while the exhaust was being cleaned with urea injection. In case absolutely obliterating a single rear tire on stock power isn’t enough for you, these engines put out enormous numbers with a few modifications. Without deleting any emissions hardware, BMW diesel specialist JR AutoTuning Performance can add a claimed 70 horsepower and 60 lb.-ft. of torque to a 335d, turning it into a straight-line monster. Best of all, you never see 335ds with low mileage – these M57 engines are absolute workhorses that just keep on trucking, a stark contrast to the 335i’s fickle nature.
For its tricky sophomore act of modern diesel inline-sixes in America, BMW pulled the N57 diesel inline-six out of its hat, expanding the North American diesel lineup to cover the F10 5-Series with the 2014 535d. It saw a reduction in output over the 335d to 255 horsepower and 413 lb.-ft. of torque, but the N57 engine fit the recession recovery better than the amped-up M57. Car And Driver called the 535d “the model to get if you want an efficient 5er” and this diesel midsizer developed its own cult following as an effortless mile-muncher.
After introducing the current G30 5-Series for 2017, BMW decided to bring the diesel back from a one-model year sabbatical by doing things big. Rather than keep the old N57 diesel, BMW developed a brand new diesel inline-six called the B57, based around the firm’s current modular engine architecture. Output in turbocharged American trim was a solid 261 horsepower and a gargantuan 457 lb.-ft. of torque, absolutely crushing the output of its predecessor. Fuel economy was good too, returning an official 26 mpg city, 36 mpg highway, and 30 mpg combined. That’s a huge bump over the gasoline-powered 540i xDrive’s figures of 20 city, 29 highway, and 23 combined.
Funnily enough, the American-spec 540d xDrive is one of the more egregious examples of BMW fudging alphanumerics. The same 457 lb.-ft. state of tune was available in Europe as the 530d, but the American 530i featured a four-cylinder engine, so a bigger number made more marketing sense. Remember, the numbers have never consistently correlated with displacement. E30 325e with a 2.7-liter inline-six, anyone?
Sales of this diesel wonder kicked off in February of 2018, with the cheapest 540d stickering for $62,995. While options could send the sticker sailing well past the $70,000 mark with alarming ease, the 540d xDrive only carried a $2,495 premium over the gasoline-powered 540i xDrive. Considering the significant bump in fuel economy, that feels like an entirely reasonable upcharge.
So how did road testers like it? Well, American road tests are virtually nonexistent, but Evo magazine claimed the diesel was the engine to go for over the gasoline-powered inline-six. In a 2017 road test of the G30 540i, the publication noted:
“Truth is, the 540i’s initial flourish of ‘personality’ is no more than a brief acknowledgment to the great naturally-aspirated sixes of the past. Its linear delivery and monotone voice, strained at higher rpms, mean it soon loses that lustre, whereas the 540d’s 457 lb.-ft. punch in the kidneys and accompanying delivery – charismatic, deep and gravelly, but superbly refined – never fail to be satisfying. Despite its livelier top end, the 540i feels no faster in the real world, uses more fuel and sounds less appealing.”
The 540d sounds like a rare case of having your cake and eating it too, but only a few got their hands on this baked delight. Unfortunately, the U.S.-spec 540d xDrive was canned by September of 2018 and reportedly removed from BMW’s online configurator, meaning it had a sales life of just seven months or so. In case the past decade is all a bit hazy for you, a massive emissions cheating scandal called Dieselgate effectively killed the future of diesel passenger cars in America, so no more diesels for us. Thanks, Volkswagen.
Crazier still, the death of the 540d xDrive coincided with BMW discontinuing its entire range of diesels in America for the 2019 model year. Mind you, it wasn’t a huge range: In addition to the 540d xDrive, BMW also sold the 328d with the N47 four-cylinder diesel engine and the X5 35d with the N57 diesel inline-six. However, that does make the G30 540d xDrive the only vehicle to be sold in America with the B57 diesel engine and the only BMW on the CLAR platform to get a diesel in North America. How’s that for exclusivity? Plus, the 540d had the latest platform introduction of any diesel luxury car sold in America. The big TDI Audi sedans predate the G30 5-Series, and Mercedes-Benz never sold a W213 E-Class with a diesel engine here.
Should you wish to buy a 540d xDrive today, you’ll have to shell out some big bucks. These rare late-model 5-ers routinely list in the neighborhood of $40,000 [Editor’s Note: I see a few near me for $26,000. Not bad! -DT]. One of the cheaper 540d xDrives I’ve seen recently hammered for $37,000 on Cars & Bids back in March, and it was a Canadian car located in British Columbia. However, maybe I’m developing brain rot, but that sort of money in today’s market for this rare gem of a car almost feels reasonable. You get all the luxuries of a new BMW, effortless diesel efficiency, and guaranteed rarity points all at the same time. Plus, the B57 is an extremely common engine overseas, so it’s not like hunting for spare parts is a needle-in-a-haystack affair. As far as modern, complex Holy Grails go, the 2018 540d xDrive is one worth keeping for eternity. Or at least for 19 years, when the first Euro-spec G30 diesels start to be legal.
(Photo credits: Cars & Bids, Lincoln, BMW)
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I have a customer with a rather rare 760ld bmw, only one I’ve ever seen. I wasn’t aware they existed until he purchased this one, drove across the country to get it.
The M57’s reliability is a bit overstated, as it has its own foibles to deal with. Things such as:
And I’m not even mentioning the expensive emissions components that fail past 100k miles, leaving you the (legally and environmentally questionable) option of deleting the emissions components or shelling out a lot of money to replace the EGR system, DPF, DEF tanks/injectors, swirl flaps, etc.
Not trying to be a downer, just giving a dose of reality here. This is from my experience running an independent BMW shop, along with several other BMW shop owners that I’m friends with.
I guess that explains losing upwards of $50k in value in just 5 years even in today’s market.
Yeah. That’s the case for almost every modern BMW, they’re tremendously expensive to repair when things go wrong, so people sell them cheap when they’ve had enough.
I’m a pretty big BMW fan, because I hate money, and I had NO idea these existed. Honestly I had forgotten about BMW diesels after the E90 335d. I did get my hands on one of those once and it ripped. I think they were all automatics given the high torque and RWD set up. It would have been a blast with the six speed from the 335i.
Luck-barges are so great for diesel. Smooth acceleration of all that weight, plus you are usually used to premium fuel prices.
I kinda feel like the better contender for this would be the 2015 BMW 740lD X-drive.
Imported for a single model-year, the only 7 imported to the US with a diesel, and possibly the most reliable 7 since the E38. Mine is possibly the most undemanding BMW I’ve ever purchased, while also the most fun.
That’s awesome! I wonder how many of those 740d’s were sold in the US? I don’t know that I’ve ever seen one…
I had a 2011 335d and all that torque in the e90 chassis could be a bit of a hoot. Scared the bejesus out of a few passengers who weren’t expecting to be pinned back in their seats quite so firmly on a few local on-ramps.
There were roughly 400 imported, all told. Pretty sure I’ve owned the only two in my state (mine, the ex’s).
And yeah, the torque is amazing. I towed a Land Cruiser last week (because I enjoy balance in life, my other car is a 4Runner, and I’m part of a Toyota off-roading group), and frankly the BMW diesel makes for a great towing platform. It’s one of the only cars I’ve owned that seems equally comfortable doing 120 as it does winding down canyons. It handles a lot better than the size would indicate.
Shame VW had to go and ruin diesels.
I had an X5 with the N57 diesel, it was awesome. Dreamed about the B57 in an X7 M50d but sadly they crushed my hopes of getting it in the US, used to joke I was gonna go to SC and steal one before it got on the boat to Europe.
a bit more short lived than the Ford f150 Powerstroke, but man it seems like a bad deal for the good stuff to come out so late and then get killed by the AOC crowd.
What well thought out and powerful comment. It had nothing to do with corporate fraud…
MrPink, well… I mean… It did have to do with corporate fraud, but part of why they felt the need to cheat was because of how wildly strict the rules became in a short period of time, the strains that caused their engineering program to make these wildly complicated and expensive emissions components actually become reliable with only a couple years of R&D time.
I wouldn’t necessarily call it the “AOC” crowd, because tier 2 CARB and EPA rules were passed under the Bush II administration… But, I can’t say I completely disagree with the general idea that government rules tightening NOx regulations 10x over the course of just a couple years did not put huge strain on automotive engineers to make work exceedingly complex equipment we didn’t have to deal with be reliable over the long term with only a couple years of development time.
Being I’m a VW diesel guy, I’ll go off on a bit of a tangent on this.
2006 diesel cars were allowed to emit 0.7 g/mi NOx.
2009 and newer that met tier 2 bin 5 rules were allowed only 0.07 g/mi. Exactly a 10x reduction from what the 2006 cars were allowed. And not many in 2006 felt those cars were exceedingly dirty at the time…
Those 2006 cars had 3 emissions devices:
Diesel oxidation catalytic converter
High pressure exhaust gas recirculation system (EGR for short from hereforth)
That’s it. Pretty simple.
2009 and newer cars? Strap in…
Diesel oxidation catalytic converter
High pressure EGR
Low Pressure EGR
Diesel Particulate Filter
Either a Lean NOx cat OR the following:
Selective Catalytic Reduction (SCR) with diesel exhaust fluid system, meaning there’s a special tank to hold this fluid, a pump, a level sensor, a fluid quality sensor, a heated hose to route the fluid and unfreeze it when cold out to get to where the exhaust fluid injector lives, in the exhaust system just before the SCR cat.
The two EGR systems, Lean NOx trap or SCR w/DEF systems all focused on helping to reduce NOx.
So, not only were these cars to emit 0 particulates thanks to the invention of the particulate filter, but they’re also saddled with multiple systems with which to reduce NOx. Go on any car forum for modern diesel cars, let me know how many people have complaints about how unreliable these complex, expensive systems are.
Long gone are the days where diesels were actually simpler than most gas engines and required less maintenance, all thanks to government requirements.
I’m not saying that the continued pursuit of cleaning up air quality is something we should stop altogether, but what I am saying is all the low hanging fruit have already been picked, and now we’re making cars needlessly more complex and LESS reliable for the sake of diminishing returns towards the end of making our air that little bit cleaner. There are other sources of pollution with little to no regulations, maybe it’s time we hit the pause button on car regulations and focused on those other sources some more to get more effective results. That’s all…
I should probably also add that with all of that extra equipment comes a whole host of sensors diesels didn’t have before as well, to monitor how effectively all aspects of this extra equipment are working.
Where most pre-2006 diesels don’t even have 1 exhaust gas temp sensor, there are now 4 per bank on the 2009 and up models (of course on a 4 cylinder, there is only the 1 bank).
There are also two differential pressure sensors. One for the particulate filter, one for the low pressure EGR filter (for the turbo’s sake, since the exhaust gas recirculation on the low pressure side is getting recirculated at the only part of the intake stream that is low enough pressure to actually draw it in: the compressor inlet of the turbo–you don’t want solid particles hitting the compressor blade of your turbo over time). These allow the computer to know when the filter has gone beyond a certain threshhold of holding onto the soot, and the computer will trigger a “regeneration” event, where it changes the injection programming to inject extra fuel on the exhaust stroke to make the exhaust gas temperatures extra high to convert the trapped carbon into ash. Once converted to ash, exhaust gases still can pass through the cells in the particulate filter.
What else is there? A couple of NOx sensors, which they never had before. Most diesels 2003 an older don’t even have an oxygen sensor, because air/fuel ratios really are just a suggestion on a diesel. They can run 20:1 all the way to 100:1, their lean-running nature is primarily why diesels create more NOx than gas engines, but also why diesels create much less Carbon Monoxide and unburned hydrocarbons than gas engines. VW started using an upstream O2 sensor in 2004 to help more accurately dial in EGR flow rates rather than relying on the drop in air flow reading at the mass air flow sensor.
Those NOx sensors are expensive as hell. They basically have their own mini computer as part of the sensor assembly, then sends data back to the main engine computer on its own LIN bus or via CAN bus depending on what car we’re talking about.
I kept hoping that this was kind of like the 1970s was for gas engines, where the first smog laws meant many compromises were made with the technology available at the time, they ran worse, people would swap out carbs and do other modifications to get them to run more consistently, but in an area that tests for smog, they would catch that it’s emitting more of one or two pollutants than is allowed, and you’d have to put it back to how the factory had it to be compliant. Engine power plummeted.
But, as you get into the late ’80s and on into the ’90s, electronic fuel injection having been well-developed by then, reliability actually improved to being the best the automotive world had, they were much cleaner and started making more and more power.
The interesting thing with diesels is right away with all this new tech, they were making more power than ever before. Much higher injection pressures, the ability to have multiple injection events per power stroke to really fine tune how they run both for emissions and power reasons, plus the particulate filter in place to catch any excess soot that is generated, yeah, they can make a good bit more power now and still be compliant.
But, it has come at an insane added complexity that doesn’t seem to be able to get simpler very easily. And even nearing 15 years on from the initial implementation of much of this technology, it still doesn’t seem like it’s gotten much more reliable or cheaper like we had from the mid 1970s on into the early 1990s for gas engines.
I should probably have added a pre-qualifying statement.
I do not endorse the fact that there was widespread cheating across multiple brands. Those who were caught were justly punished, and I don’t disagree with that.
But, bigger picture looking at everything that I know about diesels and their modern complex emissions systems as well as the change in regulations, when and why, a part of me is more forgiving to the automakers than the general public because I know this has all been a giant headache with regulations that were stepped down dramatically in a very short period of time.
It was not easy to get to where they needed while maintaining the drivability and reliability targets they desired.
With all that being said, I keep finding myself back in diesels made before 2007, because it’s honestly cheaper to buy one of those for cheap, fix up whatever neglected items the previous owner failed to do, and keep motoring. Whereas I know what waits with the more modern ones, just a lot more complexity for me to put my hands on, more money to repair in parts cost and questionable longevity compared to the old stuff.
With that in mind, the best diesel sedan that was ever put together just might be the 2005-2006 Mercedes E320 CDI with the 3.2L straight 6. Just before any of the problematic emissions devices, the last of the Mercedes straight 6 diesels before they went to V6, and the W211 is honestly a pretty nice car to be in. Makes good noises, makes decent enough power while still being pretty quiet and can still regularly get high 30s MPGs with 369 ft-lbs of torque under your right foot.
It’s kind of the sweet spot of just modern enough while not having the added headaches of anything newer.
not gonna say I read it all. I will. I will also say I am in the market for a ford 7.3 single cab 250 or bigger for a slide in (thought I found one with a tray bed). I don’t want the issues of newer motors. I’ll buy a 20 yr. old truck instead of what people used to do – delete. But it is chipped. So it’s out for me due to the current EPA enforcement. Enforcement of laws that were ignored by enforcing agencies for years until the the corporate fraud and the choo-choos. So who ruined it? The rolling coal boys or the aftermarket that sold the add 50 75 100 150 hp tunes? And the 150 rolls the choo-choo coal! Yeaaa? The choo-choo trains with the soot broke the law and the camels back so egregiously that the government is/has to shut it all down to save face. Yes the tech could/would get even better. The beemer in this piece sounds great, I loved my 535ix wagon but didn’t need the top end so much, I like torque from low rpm.
“the optics” on diesel didn’t/couldn’t work anymore. Did you talk about the sulfur? It seemed the more tech advanced the more the higher content USA fuel caused issues? Or is there a new coke diesel in USA? Anyway you provided a lot of good information thank you.
I think we more agree than disagree. The rapid changes is emission regs. was not “fair”. It says to me the interested parties had the wrong or were not paying their lobbyist enough! I’ll bet you the US manufacturers never thought the combo of the Euro’s cheating and the coal rolling would make their ability to sell diesel trucks even harder.