N54 vs N55 vs B58 vs S55
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BMW N54 vs N55 vs B58 vs S55: Performance & Reliability

About Zach Mayock - DieselIQ

Meet Zach

Zach is a BMW enthusiast with a passion for performance. With over 10 years of experience modifying and performing DIY work on BMWs, he’s developed a deep understanding of virtually every BMW engine. He’s also the proud owner of a 600whp N54 with upgraded twin turbos and an E30 325i drift car and has a particular affinity for the S58 engine. Zach is highly knowledgeable about all things BMW, but his expertise in tuning and performance mods sets him apart. His experience as an enthusiast, combined with his technical knowledge, makes him an essential resource for anyone looking to improve the performance of their BMW.

Ever since the twin-turbo N54 hit the market in the 2007 BMW 335i, BMW has been building on the design of the turbocharged, direct-injected inline 6 engine. In 2010, the 335i received the updated N55 engine followed by the B58 in 2016, however, the model was rebranded to the 340i. Unsurprisingly, the success of the turbocharged inline 6 led to its introduction in the F80 BMW M3 beginning in the 2015 model year.

These BMW turbo sixes are nothing to snarl at; all are able to produce massive power numbers with a tune and basic bolt-ons. Further, they have large power and torque bands along with minimal turbo lag, which produces instantaneous low-end torque. How do the BMW N54 vs N55 vs B58 vs S55 stack up against each other?



Since the initial release of the BMW N54, the engine has gained quite a positive reputation in the tuning community. Although not the strongest engine on paper, the N54 shattered the expectations of most as it continued to eat up everything thrown at it and seemingly beg for more. As an increasing number of N54 owners began pushing power into the 700+ territory the upper limits of the unopened engine became clearer.

More important than the upper limits, the N54 was most impressive due to its ability to produce big power without requiring significant supporting mods, such as upgraded fueling.

BMW N54 Specs

Stock Power: 300 HP
World Record HP: ~1,005WHP
Displacement: 2979cc (2.979L)
Turbocharger: Twin turbo
Compression: 10.2 to 1
Bore x Stroke: 84.0mm (3.31”) x 89.6mm (3.53”)
Internals: Forged crank and rods. Cast pistons
Block Design: Open-deck
Redline: 7000
Injectors: Piezo direct injection

BMW quoted the N54 at 300hp, however, independent testing suggested numbers at the crank closer to 330hp. Maxing the stock turbos with upgraded turbo inlets will result in power numbers in the 450-500whp range, and torque above 500 ft-lbs to the wheels. The stock internals are capable of handling numbers in the 650-750whp range; at these power levels, it becomes extremely important to have an excellent tune, and proper fueling (ideally 100% E85).

Open-deck blocks and cast pistons are not great at handling extreme boost pressures for long periods of time. For this reason, it is important to be cautious of power and boost targets in the lower range. The pistons are traveling slower at lower RPMs, which results in the high boost pressure sitting in the cylinder for a longer period of time.

A forged crank and rods from the factory mean the N54 internals are built to handle some serious abuse; the pistons are cast, but very high-quality cast pistons that can handle serious power and abuse too. Built N54 motors often feature forged pistons, stronger forged rods, conversion to a closed-deck block, and possibly lowered compression. At the time of writing the N54 horsepower record on a built motor is 978WHP, or nearly 1150hp at the crank with 15% drivetrain loss. Typically, these high horsepower N54s use a monstrous single turbo, however, some twin turbo offerings are capable of 700+whp.

BMW N54 Reliability

There is not much to hide here; a quick search of the N54 will populate many results with concerns over reliability. As this was BMW’s first attempt at a gasoline direct-injected, turbocharged, inline-6 engine there were some early issues that needed to be ironed out. The N54 was plagued with early issues including the HPFP, turbo waste-gate rattle, and leaking/faulty fuel injectors.

Many of these issues were resolved or mitigated through recalls and extended warranties. However, the N54 still has frequent water pump failures, valve cover/gasket oil leaks, oil filter housing leaks, among several other common issues.

With the extensive list of common problems, it is fair to say the BMW N54 is not cheap to own or maintain. We do believe it is better than some suggest, however, if you take the car to the shop for every minor issue and do not DIY any repair jobs the bills can certainly add up quickly.

Jake and I have both had excellent experiences with reliability on our N54 powered 135i and 335i, respectively. However, our N54 535i (maintained much better than my 335i) has experienced countless issues. Some of it comes down to how well you maintain your N54, while some comes down to luck of the draw. Nonetheless, you must pay to play and the N54 is no exception.

Overall Thoughts on the BMW N54

Reliability Rank: 4

Tuneability Rank: 1

Value Rank: 1

**Ranks are as compared between the four turbo, inline 6 engines**

1 = Best

4 = Worst

In the BMW N54 vs N55 vs B58 vs S55 fight, the N54 earns the worst score for reliability. Fortunately, BMW learned its lesson on the N54 and focused on improving the reliability of its future turbo engines. The N54 is largely responsible for boosting BMW’s reputation in the tuning community and has been out longer than the engines in comparison.

Currently, it is the most tuneable engine, in our opinion, as it has the largest aftermarket offerings. Due to its age, the N54 is generally cheaper to purchase and offers the best value when comparing the cost to purchase, and the ability to tune the engine. However, the initial value of purchasing the N54 may diminish due to potential reliability issues.


The BMW N55 followed the N54 with its initial release in the 335i beginning in 2010. Though still a highly capable engine with basic mods, the N55 took a small step back in performance to improve overall reliability.

Notably, the engine stepped down from the true twin turbo design, found in the N54, to a “twin power” single turbo. The single turbo in the N55 is a larger turbocharger that produces the same power as the N54, stock for stock. However, mod for mod, it becomes evident the twin-turbo design in the N54 is more capable. Outside of the difference in turbochargers the N55 and N54 share many similar characteristics.

If you are interested in learning about the BMW N55 engine in more detail, take a look at out Ultimate BMW N55 Engine Guide.

BMW N55 Specs

Stock Power: 300 HP
World Record HP: ~750WHP
Displacement: 2979cc (2.979L)
Turbocharger: “TwinPower” Single Turbo
Compression: 10.2 to 1
Bore x Stroke: 84.0mm (3.31”) x 89.6mm (3.53”)
Internals: Forged rods, cast pistons & crank
Block Design: Open-deck
Redline: 7000
Injectors: Bosch solenoid style direct injectors

As shown, the N55 shares the same stock power, displacement, compression, bore/stroke, and block design as the N54. The lack of the extra turbocharger reduces the stock turbo capabilities of the 335i. Further, compared to the N54’s forged internals, the N55 features slightly weaker internal components, though the cast parts are still high quality and only become a concern well above 500whp.

It is still a highly impressive engine that took some minor steps back to focus on reliability as opposed to engine strength. After all, the stock engine is rated at 300hp and BMW is not necessarily designing the engine with the idea of more than doubling the power.

BMW N55 Reliability

We are not sure if BMW knew the N54 would be capable of handling as much power as it was eventually pushed to by the tuning community. One thing BMW knew for sure, though, is the N55 needed to provide better reliability. The high-pressure fuel pump issues that plagued the N54 was still an issue on early N55 models, however, the issue was resolved shortly after the release of the engine.

Injectors were changed from the piezo style to solenoid style as the piezos had too many issues on the N54, were too expensive, and did not live up to expectations. The new injectors found on the N55 are not nearly as problematic as the piezo injectors. Lastly, issues with waste-gate rattle were mostly resolved on the N55.

Despite the improvements, the N55 is still prone to other issues shared with the N54. These include common problems with the water pump, valve cover and gasket, and oil filter housing and gasket. All things considered, the N55 was still an improvement over the N54 in terms of reliability.

Overall Thoughts on the BMW N55

Reliability Rank: 3

Tuneability Rank: 4

Value Rank: 2

Though the N55 does not earn the highest marks for reliability, it is not to suggest the N55 is a terribly unreliable car. It is more of a testament to just how good the two remaining engines are. When comparing the N54 vs N55 vs B58 vs S55, the N55 comes in third in terms of reliability. BMW’s B58 and S55 engines are newer, so more issues may pop up down the road.

Compared to the two former engines the N55 has been on the road longer, allowing for additional time for tuning developments. There are more tuning options available, however, the N55 single turbo design limits its tuneability as compared to the twin-turbo S55. Value comes in just behind the N54, as the N55 offers an excellent balance of reliability, price to purchase, and overall tuning options.


Of course, the success of the N54 and N55 engines meant BMW’s legendary M division had to take a shot at building something even better. Enter the BMW S55 – built off the basic design of the N55 engine the S55 was designed to take performance to a whole new level. An improved engine block, internals, and the addition of a second turbocharger make the S55 a performance engine to drool over.

Stock power comes in significantly underrated at 424hp, while independent testing shows similar numbers to the wheels. In our opinion, BMW nailed the design and specs of the S55, and it is truly the most capable engine in this comparison, by a long shot.

BMW S55 Specs

Stock Power: 424 HP
World Record HP: 1150WHP (~1350 crank horsepower!)
Displacement: 2979cc (2.979L)
Turbocharger: Twin turbo
Compression: 10.2 to 1
Bore x Stroke: 84.0mm (3.31”) x 89.6mm (3.53”)
Internals: Forged crank and rods. Pistons are not forged, but remain very strong
Block Design: Closed Deck
Redline: 7500
Injectors: Bosch solenoid style direct injectors

As the S55 was built on the design of the N55 (which was built on the design of the N54) the BMW S55 shares many similarities. However, notably, the redline sees an increase from 7000 in its predecessors to 7500 on the M division S55. Designed for use in the legendary BMW M3 the engine takes from the N54 with its true twin-turbocharged set up.

Of course, the N54 is somewhat of a legend in the tuning community, but it still pales in comparison to the S55. Just about every part of the S55 is bigger, better, and stronger than the N54. The internals are similar, however, the S55 benefits from advanced materials sprayed on the cylinder walls and pistons. Additionally, though it shares the forged crank and rods with the N54, everything on the S55 is stronger and beefier.

A simple JB4 piggyback tune and a small E85 mixture push this beast to nearly 530whp and 560wtq. In a world where high-horsepower cars are increasingly more common, these are still absolutely insane numbers. Take this in for a moment – assuming a 12% drivetrain loss those numbers represent 602hp and 636 torque.

Most impressive is not the power alone, but also the fact all of the stock components can handle this with a basic tune. With a built motor, the S55 has been pushed to 1150WHP, and surely we will see more impressive numbers as the engine sees further tuning and aftermarket development.

BMW S55 Reliability

The BMW S55 has proven to be an exceptionally reliable engine over the course of its 9-year lifespan. The vast majority of S55 engine problems, with the exception of a couple, are relatively minor in the grand scheme of things. Most of the S55’s problems revolve around cracking plastic, i.e. the charge pipes and valve cover, and worn gaskets, like the valve cover gasket and oil filter housing gasket.

Crank hub issues are a more substantial problem that seems to also affect a small number of S55 engines. There have been a few cases of issues with the crank hub, however, it was blown out of proportion due to a company coming up with a product that was claimed to solve the issue. In reality, it was worse than the factory part. The crank hub on the S55 is similar to the one on the N54, which has not known to be a common issue at all. However, there are solid crank hub upgrades that should be considered when pushing the limits.

The main coolant pump on the S55 is belt driven, which holds up much better than the electric water pump found in the N54 and N55 engines. Valve cover and oil filter housing leaks are common on a lot of BMWs and the same can be said for the S55. BMW’s S55 engine is without any serious “common” issues even when modified, so this engine earns high marks for reliability.

Overall Thoughts on the S55 Engine

Reliability Rank: 2

Tuneability Rank: 2

Value Rank: 3

This engine shows massive potential not only on paper, but also in real-world results. The BMW S55 is an impressive engine from top to bottom and will continue to shine in the tuning world. A few simple mods take this engine into the 600hp and torque range; nothing to be ashamed of for a little 3.0L inline-6.

The BMW S55 ranks number 2 in reliability, mostly due to the fact that it doesn’t have quite the same amount of aftermarket support as the N54. Despite not having quite the catalog of the older BMW twin-turbo inline-6, anything that you could possibly want in order to make big power from the BMW S55 is available at this point. Coupled with the S55’s robust architecture, a very strong case could be made that the S55 has one of the best aftermarket scenes in the modern BMW space.

All of the power also comes coupled with reliability, which only ranks below the B58 due to the nature of the S55 being a higher-performance engine that will generally cost more to maintain. Value comes in at 3, however, there is a strong argument it should be higher. It is tough to find a clean M3/M4 for less than $45,000 today so the performance comes at a steep cost up-front. Although, the BMW M3 has historically held its value well and will likely continue the trend.


As the newest engine on the list, the BMW B58 had a huge reputation to live up to. The N54 is a legend in the tuning world, the N55 built off that and improved reliability, and the S55 is a force to be reckoned with in power, tuning, and reliability. Did BMW live up to that reputation? Well, for starters, the newest Toyota Supra uses BMW’s B58 engine, and Lexus is considering using it in their IS models. Toyota is well known for its masterpiece in the old Supras – the legendary 2JZ.

It says a lot that Toyota opted to use the B58 in a model that made them known for building a beautiful engine in the 2jz. Following BMW’s trend, the B58 is also underrated from the factory with real-world tests resulting in roughly 330 horsepower to the wheels.

BMW B58 Specs

Stock Power: ~330hp
World Record HP: ~900WHP
Displacement: 2998cc (2.998L)
Turbocharger: Single “Twin Power” Turbo
Compression: 11.0 to 1
Bore x Stroke: 82.0mm x 94.6mm (3.23in x 3.72in)
Internals: Forged crank and rods. Cast pistons.
Block Design: Closed Deck
Redline: 7000

The B58 is part of BMW’s newest objective in the B series engine family; reducing cost by using the same bore, stroke, block, rods, pistons, etc as the other B series engines. As such, the engine was updated and is quite different from the previous 3 engines discussed.

Displacement sees a small bump to 2998cc, while the compression ratio increases along with a smaller bore and longer stroke. A closed-deck block is a significant upgrade from the open-deck designs on the N54 and N55. Additionally, it receives the forged crank and rods as with the N54. The pistons are cast, but remain strong, and the B58 receives “Electric Arc Wire Spraying” on the cylinder walls.

Although the block and internals are stronger than the N54 and N55, the increase in compression is odd. Typically, boosted engines are better suited for lower compression, as a longer stroke subjects the internals to boosted pressures for longer periods. With that being said, the B58 is still capable or around 650 horsepower and 600wtq with stock internals. At that point, the rods and bearings start to enter the danger zone. To learn more, take a look at our How Much Power Can the BMW B58 Handle Article.

On paper, the B58 matches, if not slightly exceeds, the N54 for strength and durability. Although, the single turbo will likely limit its capabilities without upgraded turbo(s). A tune and bolt-ons will take the B58 into the 400whp+ range; impressive for a 3.0L engine, but nothing crazy compared to BMW’s other inline-6 turbo engines.

BMW B58 Reliability

In quite a few enthusiasts’ opinions, the BMW B58 is one of the most reliable turbocharged engines that BMW has ever made. Unlike the BMW N54 and N55 engines on which it was based, BMW has resolved almost all of the high-ticket repair items that were common problems previously. For example, there aren’t endless cases of waste-gate rattle, HPFP failures, or fuel injector failures on the B58.

While most of the major issues have been resolved at this point, the B58 still experiences many of the same basic wear and tear issues that we have all come to know and expect from turbocharged BMW engines at this point. Failing VANOS solenoids, leaking valve cover gaskets, and PCV valve problems are all still par for the course. Fortunately, there is not much more to discuss with regard to BMW B58 reliability.

Overall Thoughts on the BMW B58

Reliability Rank: 1

Tuneability Rank: 3

Value Rank: 4

When we initially wrote this article in 2019, we were optimistic and excited to see the true potential of the BMW B58 realized. Well, here we are 4 years later and the BMW B58 is still considered one of BMW’s most reliable, modifiable, and versatile turbocharged engines. Overall, our opinion of it hasn’t changed since then, we’ve just been lucky enough to see the aftermarket space do some incredible things with both B58-powered BMWs and with the MkV Supra.

In the years to come, the B58 will be an excellent performance value, and in some cases it already is. B58-powered F3X cars are nearing the bottom of their depreciation curve, making them fantastic value for money. With that being said, so are F8X M3/M4s. An S55-powered M3 can be found for roughly $10,000 more than a B58 car. The B58 is a great engine, but the S55 is better. Much better when you consider you get the full package in the M3. For that reason, the B58 scores the worst value rating.

The B58 is an incredible tuner/mod-friendly engine. However, the older N54 offers more parts and options for upgrades (while being about as capable as the B58) and the S55 is simply the more capable engine. Reliability scores the highest marks compared to the N54, N55, and S55.

Final Thoughts on the BMW N54 vs N55 vs S55 vs B58

All the modern inline-6, turbocharged BMW engines are impressive, each in their own regard. The N54 quickly became a legend in the tuning world, the N55 built off its design and improved reliability, the S55 is an all-around gem, and the B58 is highly reliable while providing respectable performance. Of course, we are biased towards BMWs here at BMWtuning.co, but we fell in love with these modern turbo BMW engines for a reason. Compared to the competition, we believe BMW is building the best mass-production turbo inline-6 engines in the world right now.

Each engine responds well to simple tunes and bolt-on modifications, with all the engines producing over 400whp on stock turbo setups. Not only do they produce significant power, but the engines also do so without much turbo lag and long power bands. Additionally, BMW built on a great engine design in the BMW N54 and continued to improve the reliability of the succeeding engines. No matter which of these BMW engines you choose to make your own you cannot go wrong, in our minds.

Which of these BMW turbo inline-6 engines is your favorite?

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  1. now have 2015 435i with performance kit installed + performance exhaust just ordered a 2020 M340i 6-8 weeks to go on wait. 2015 335i 4 series coupe has been a great auto. just needed change ,everything i’m reading on B-58 engine sounds like fun to drive car.

  2. I have a 2011 535i M Sport with 200k miles. Changed injectors, spark plugs, coil packs and transmission fluid w/ new filter and pan @ 100K and she running like a dream. Replace valve cover gasket and oil pan gasket at 160K. Injectors are getting loud again at 200k so its time to replace them. Last replaced plugs and coils at 190K. Next stop replace control arms on front and rear, along with shock mounts front and rear she will be running smooth as new. Trust me she still has a lot of life yet to go.

  3. Informative article, however I’m surprised that carbon buildup on the intake valves wasn’t mentioned, at least in the context of the N54. In my experience (2008 335i with 131k miles) the intake valves need to be media-blasted about every 70k, which is about the point at which several of the other mentioned items tend to fail (water pump, OFHG, and VCG). I imagine a lot of (even most?) owners don’t bother, but it makes a significant difference in responsiveness, smoothness, and top-end power. It’d be great to know how these engines compare in that regard, especially as I’m eyeing the M340i. 😉

    1. Hi Jack,

      Thank you for your comment. Great point regarding walnut blasting. We did not include that as we do not consider carbon build-up an “issue”. Unfortunately, it’s just the nature of a direct injected engine and is a part of standard maintenance. Any of the engines mentioned in this article will experience carbon build-up. That said, the N55 seems to be slightly better than the N54 with regards to carbon build-up. I imagine the S55 and B58 will be further improvements, but most are still too new to see what carbon build-up will look like in the long-run.

      It also comes down to each specific engine. One of our N54s went 113,000 miles before its first walnut blast. Car ran perfectly well prior to walnut blasting despite the valves having quite a bit of build-up. Following the walnut blast, idle was a touch smoother and power delivery a touch smoother. It cleaned up ignition timing a little bit, too. However, it wasn’t as drastic of an improvement as some say. The butt-dyno felt no power gains. Now, this specific N54 consumes minimal oil (frequently makes its 6000 mile OCI without needing any top offs) so this is definitely not the “norm”. Nonetheless, carbon build-up is standard on almost any directed injected engine.

      Best Regards,


    1. Hi DeeVee,

      Haha we’re always down to go harder and push things to the limit. Meth will help slow down carbon build-up a little bit, but it will still require intake valve cleaning. Outside of that, meth definitely has some great performance benefits.

      Best Regards,

      BMW Tuning

      1. I’m looking for my first sports car and BMWs seem very nice. My question is what are the running costs for them (a ballpark mainly). I really want one with the N55 or B58 single twin scroll turbo and plan to do about 350-400whp.

        1. Hi Michael,

          That’s really hard to put a number on since it can vary so much. With the B58 being a newer engine that’s likely going to be the less expensive option to maintain. We also think the B58 should hold up a bit better as it ages. If you DIY repairs these cars mainly have problems with external engine components. It’s stuff that is pretty cheap to DIY.

          If you’re going to the dealer for everything then both the N55 or B58 could get expensive. Most repairs at the dealer will easily run over $1,000. Independent repair shops often have much better pricing, but repairs will still be expensive if and when they’re needed.

          Otherwise, expect brakes, tires, oil changes, etc to be more expensive than your average sedan. 350-400whp will require at least a decent set of performance tires. Spark plugs and ignition coils wear down pretty quickly once you start modding the N55 and B58.

          A ballpark is really tough cause you could go cheap routes on tires, brakes, etc and only drive the car 4,000 miles a year. Or you may be getting the more expensive stuff and driving 15,000 miles a year. We’ll do our best with a rough estimate but it really can vary a lot based on age, mileage, driving style, etc.

          DIY everything – $300 to $750 a year
          DIY the basics (oil, brakes, spark plugs, etc) – $500 to $1,200 a year
          Repair shop for all work – $1000 to $2,000 a year

          Best Regards,
          BMW Tuning

  4. Just bought a 2017 340i and I really love the B58 so far. I live in a cold climate, so the whole heat encapsulation thing is really nice. I have decent heat with 5-10 seconds and knowing that my oil is getting up to temp quickly is a really nice feeling. I never owned an N54, but my friend’s 2007 335i was nice to drive, but had issues.

    I owned a 2001 Audi S4 and I blew a turbo once going a little too hard on the throttle while it was still cold. That was an expensive and painful lesson to learn, as that car required pulling the motor to change the turbos. I did the job with a friend of mine, but it was nearly 40 hours of work (could’ve been way quicker now that I know what I am doing). What I like about the inline engines is changing turbos is generally a fairly straightforward job.

    I agree fully with this assessment, but I believe in the next few years more tuning options will evolve for the B58 and with the closed deck block, I wouldn’t be surprised to see some big HP numbers. Steph Papadakis and his boys are making 1000HP @ ~42psi on a 2020 Supra B58. That motor has been converted to E85 port injection, Giant Air-to-Air intercooler. Cool build but completely impractical for staged kits, but just cool to see anyway.


    1. Hey John,

      Awesome to hear – congrats on the new 340i! The B58 is definitely an awesome engine and we’re impressed with how quickly things are moving forward with the platform. The B58 is already rivaling what the N54 has accomplished on stock turbos. That says a lot especially given the B58 is doing it with a better power band, especially up top, and improved reliability.

      Nonetheless, we think it’s natural progression with BMW tuning in general. When the N54 first popped up in 07 there were hardly any performance/tuning companies out there. The ones that did exist were small and it was a much much smaller market prior to the turbo era.

      We think the Supra carrying the B58 helps the platform a lot, too. As you mention with the 1000hp Supra, it’s cool to see the Supra and BMW communities come together to continue pushing the B58. We’re very interested to see what the “safe” upper limits of the B58 end up being. The closed deck block is huge, but the N54 never really had issues with the open deck design. Still a sound improvement for the B58. Crank and block should be plenty strong to handle 800+whp. Just a question of how the other internals fare.

      Enjoy your new B58! Thank you for the comment.

      Best Regards,

      BMW Tuning

    2. Would your rankings remain the same when considering the “higher-end” variant B58 w/382hp? Curious as to why this hasn’t been included in any updates to the article

  5. Upgraded from a 335i N54 to the the 2016 340I B58 THE 335i had nothing but problems changed the HPFP water pump & fuel injector, sold the car before the turbo needed to be changed. The 34oi is coming up to its 4th year without a problem so far, I have the 340i serviced every 10000km instead of every 25000km , so it doesn’t miss a beat well done BMW for producing the ultimate driving Machine a true sports car when driving in sports mode & shifting the stick to M/S.

  6. Did the crank hub in the S55 get revamped for Toyota? I couldn’t imagine them using it if there was in fact an issue.
    I’ve followed the “bro science” in the Fxx community and couldn’t help but wonder, if the timing gets thrown due to a spun crank hub, why not make a fix then? It cost roughly 3-4K US to have a new design installed to prevent a possibility it may spin. What’s your thoughts on this? Great article BTW

    1. Hi David,

      Of the engines referenced in this post Toyota is only using the B58. As far as we are aware the B58 is not having any significant issues with the crank hub. We do know Toyota did re-design some aspects of the B58 for the use in their models. Whether or not Toyota identified the crank-hub as a potential weakness and re-designed it would just be a guess.

      Best Regards,

      1. Completely misread that. Thanks for the clarification and reply. Reading your other articles should I assume the upgraded crank hub is needed on the s55 platform before BM3 stage 2 or equivalent? Currently stock on stage 1. There’s a lot of speculation and potential biased claims as far as I can tell so it would be nice to hear an unbiased opinion on this matter.

        1. Hi David,

          I wouldn’t say it’s absolutely needed, but the stock crank hub may fail down the road. Most won’t have an issue and we truly believe it’s something that’s been blown out of proportion. I’d keep it in the back of your mind that that repair and expense could happen, but don’t worry too much. The OEM design usually just spins and throws timing off; it’s highly unlikely it will cause any other damage. If it fails, an upgraded crank hub is definitely the way to go. Maximum PSI seems to make a good one. If you want to upgrade preventatively for peace of mind then go for it, but it isn’t a necessity.

          Best Regards,

          1. Ok, definitely my thought process as well. Thank you for the response and enjoyed the articles. Have a good holiday weekend if you’re in the US.

  7. Great article, thank you

    I just bought a 2017 April F20 M140i x drive and I am
    ansolutely thrilled. Not quite sure wether it‘s a B58 or still the N55 thougj.. any ideas?

  8. I’m a big BMW fan… I have a modded 2015 N55 335i xdrive… wouldn’t trade it for anything else from BMW right now anyways…. B58’s threads and videos are popping up everywhere of blown pistons on the B58 at 650+/- Hp… My point is if the B58 is limited to same horsepower as a N55 then I benefit from a better handling car… 🙂

  9. Something doesn’t add up. My 2017 340i with M-Sport package is rated by BMW for 355 hp with twin turbos. Not sure which car you refer to when you say single turbo.

  10. This was a great article. I’m new to all of this. Had n55 in a 2011 335cvt, w manual. Was stock. Had the well known gasket issues. Just purchased a 2021 M340. Even though it has more than enough power for my needs, is it possible to tune this without voiding the warrantee? If possible, How much would it cost? Thanks

    1. Hi Joe,

      We appreciate the positive feedback. You can indeed tune an M340i without voiding warranty. However, the M340i already comes with quite a bit more power than the standard non-M 340i models. It basically has a more aggressive tune from the factory. Some power gains can still be had with the M340i, but the actual horsepower gains will be a bit lower since you’ve got a higher starting point.

      Dinan offers stuff that’s covered under warranty. Although, I’m not sure if they have anything for the M340i. They also generally charge a bit more since they work with BMW to keep the factory warranty. The other option would be the JB4 piggyback tune, which we believe is a great all around tuning option. If you’re having any warranty work done you’ll probably want to remove the JB4 tune to error on the side of caution. Once removed there is no way for BMW to tell the car was ever tuned. It’s a pretty simple 20-45 minute install and uninstall. Once you’ve done it a few times it becomes very quick and easy.

      Congrats on the purchase! The M340i is a beautiful car and the B58TU is a great engine. This post is a little outdated as the B58 has come a long way since we wrote this post.

      Best Regards,

      1. Thanks Zach! Really appreciate the info. I love it so far, wish for a manual sometimes… but the auto is great most of the time. What kind of HP increase could I expect with the JB4 piggyback tune? So much too learn, so little time.

  11. First, let me say this is awesome info and I’m grateful for it. Second, last night I purchased a 2017 340 with 30k. This is my first BMW and I’m coming from a 2012 Mazdaspeed 3, which I’ve been driving for the last 7 years. Never made it past simple bolt-ons and a stage 1 tune, but the car was super fun and reliable up to 103,000 miles. I’ll get to enjoy it a few more days before I say goodbye. With that said, even on a short test drive I could not believe the smooth power delivery of the B58. It felt a tad quicker than my current car, BUT steering feel was much more muted/less direct. Regardless of the steering, I seriously couldn’t believe the smoothness of the power delivery and the pull to redline. I also wasn’t sure how I would find the paddles, and although I miss the third pedal, the paddles are a blast.

    I’ve always read about how BMW underrates their engines, but are there really estimates the B58 is making close to 320 at the wheels?! If so, that’s impressive. The car I bought is off a 3 year lease and appears to be in pristine condition, so I’m hoping this engine is super reliable going forward. Happy I stumbled on this website and will definitely be reading more. Thanks!

  12. Thanks for the great read. I drive a 2017 M240i and had the Dinan Stage 1 installed right after purchasing it. Since then, I’ve been wait for Dinan’s Stage II, III and turbo, but, nada. Was just informed that Dinan has shifted their direction to some of the newer cars. Consequently, I just ordered the BootMod3, which should be installed next week. Can’t wait to compare the BM3 to the Dinan Stage 1.

    1. Hi Bill,

      We appreciate the positive feedback! Awesome car and congrats on the new tune. Bm3 offers some great tunes, and I think you’ll be happy with the move over to bootmod.

      Best Regards,

  13. Hi Al l/ Zach,
    what a great site you have! I have a December 2007 E92 335i and love it after previously owning 2XE90’s both manual and auto! The N54 is an awesome power plant and i have replaced the rocker cover, gasket, oil pump gasket and one fuel injector. it now has 125,000km on the clock and is stock 300HP. My car has been lowered with Bilstein shocks and drives like a dream. I hope to get a 2015 M3 in a few years time as i would love to drive the S55! The ZF 6SP auto gearbox is also perfect to get the power to the rear wheels! BMW really is the Ultimate Driving Machine! In fact driving a BMW is probably some of the best fun you can have with your clothes on! 🙂

    Merry Xmas all from Chris in Canberra, Australia!

    1. Hi Chris,

      We appreciate the positive feedback. Haha your last comment seems to be spot on! Same with the N54 and E9x chassis. Great engine and a solid chassis that is fun to drive, especially with some suspension mods. ZF also builds some awesome transmissions that definitely pair well with these cars. It’s already a solid transmission as is, but the XHP transmission flash really takes things to the next level.

      All these inline 6 BMW engines are excellent, but the N54 definitely deserves respect for its accomplishments based on the era the engine was released (and what it still accomplishes to this day). Enjoy the car and Merry Christmas to you as well!

      Best Regards,

  14. Hello and thanks for the great article! I have a 2011 335 x drive manual that I love. I track it and the engine has been holding up very well. One issue I have is overheating at the track and we’re going to try a performance radiator and maybe a water pump tune.

    Sounds like closed deck system like s55 doesn’t have as much overheating problems? Would a swap to s55 be ruinously expensive and difficult? Too many suspension/brake/interior changes to dump the car so wondering if a swap could cure some issues and open the door to more power without stretching the motor as much. Appreciate any thoughts!

  15. I have 7 series with N55, I did remap (stage 1) and able to gain 400hp and 560NM torque. It cost about 180 Euro. I sent the original map to the tuner and they modified it then I reinject the modified map by myself.
    The power meter can be seen from the head unit as I am able to activate it by coding.

  16. I know nothing about BMW’s and love the articles. I’m trying my best to absorb as much as I can.
    Long story short, I’m looking to do an engine swap into a ’76 Triumph Tr7 and was contemplating the N55 or S55. Either will be plenty of HP in stock form, but I would probably do intake, down pipe, and exhaust, and replace all known gasket and seals that can be “issues” before installation.

    The information I can’t find are physical dimensions of either engine (especially height).

    Are both available in RWD with manual transmission? And if they are, can the transmission ratio be changed? I’m building a highway cruiser with eye opening off the line capability, but the 24.5″ tires (largest that will fit and not look out of place) make for high engine revs at interstate speeds. The talker a 6th gear I can find the better.

    Everyone and their brother has done the LS swap and it’s become boring. I don’t want to be “that guy”.

    Any advice?


  17. I have had all 3, I had a 535i e60, with the n54. That got lemoned (hpfp issues). Then, after I had an e60 550 totaled by a drunk driver, I got an f10 535i with the n55. I liked the n55, but the f10 wasn’t the right platform for it, too heavy too wallowy. I traded that in for the current 540i with the b58, and tuned its a beast. It makes hellcat owners cry all day, every day.

  18. Absolutely excellent comparison, Zach. Thank you.

    B58 is obviously a winner. Why? Huh, B58 can make a lot of power and is the best for reliability.

    It has honestly amazingly smooth power delivery and sounds better.

    Well, I have N54 running 550whp on td04s. Too much trouble. N55 is better than the N54, but it’s just a reliability upgrade.

    B58, I want one. LOL

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