The S54 and N54 are iconic high-performing BMW inline-6 engines. Although very different in terms of design and power delivery, these are both legendary engines that will go down in history as some of the best inline-6 motors ever made.
The E46 M3 introduced the S54B32 in the year 2000 and it was praised for its revvy character and aggressive raspy tone. The S54 holds the honor of being the last naturally aspirated (NA) inline-6 engine used in a BMW M3.
Contrastingly, the N54 engine made its debut six years later in 2006, powering the 335i. It quickly garnered acclaim and awards, including numerous Engine of the Year. The N54 began to phase out with the introduction of the N55, with production stopping in 2016. Let’s compare the S54 vs. the N54 in terms of performance, tuning, reliability, sound, & cost:
S54 vs. N54 Specifications
|338 hp @ 7,900 RPM
|302 hp @ 5,800 rpm
|269 lb-ft @ 4,900 RPM
|295 lb-ft @ 1,400-5,000 rpm
|DOHC with Variable Valve Timing (VANOS)
|DOHC w/ Variable Valve Timing (double VANOS)
S54 vs. N54 Horsepower & Torque
Both of these engines make a significant amount of power from the factory, with very respectable horsepower and torque figures even in stock form. However, power delivery varies significantly between these two engines.
On one hand, the S54 has a maximum horsepower of 338 HP at 7,900 RPM while the N54 outputs 302 hp at 5,800 RPM. In terms of torque, the S54 puts down 269 lb-ft at 4,900 RPM while the N54 puts down an impressive 295 lb-ft between 1,400 and 5,000 RPM.
The S54 is a high-revving naturally aspirated engine, and most of its power lies at the higher end of the rev range. On the other hand, the N54 features two turbos, giving it plenty of low-end torque that gradually dies out in the high RPMs.
These engines have very different characters. The S54 is a high-revving NA engine while the N54 is a turbocharged torque monster.
When looking at the dyno chart of both engines, we can see how the N54 produces a high and consistent amount of torque from around 3,000 rpm all the way up to 5,500-6,000 RPM, making it ideal for those looking for usable power around the city.
The S54 on the other hand needs to be revved up high to unleash its true power potential. Revving up an S54 all the way to redline on public roads could get you into serious trouble before you even get to 3rd gear.
S54 vs. N54 Tuning
The N54 has a well-deserved reputation among the car tuning community. The N54 engine is stout, well receptive to modifications and a stock engine block can handle up to ~700 wheel horsepower and ~650 lb-ft of wheel torque reliably. A single turbo N54 with the respective accompanying bolt-ons can potentially reach an impressive 900-wheel horsepower, a feat that makes the N54 comparable to the venerable 2JZ engine of the MK4 Toyota Supra.
The N54 is more tunable than the S54, with the potential to considerably increase power with just a few mods and a tune.
On the other hand, the naturally aspirated S54 engine is not as receptive to modifications. While bolt-ons can bump power output moderately, to substantially increase the power you’ll need forced induction. There are available supercharger & turbocharger kits for a forced induction setup, but they are costly.
S54 vs. N54 Reliability & Maintenance Costs
The S54 marked the end of an era, being the last naturally-aspirated inline-6 used in a BMW M3, while the N54 represented a new direction as BMW’s first twin-turbo direct-injected inline-6 engine. This alone speaks volumes about their reliability. The N54 was indeed a groundbreaking engine that paved the way for newer turbo inline-6 engines, though early models were problematic.
The N54 is known for injector failure, water pump failure, turbo wastegate rattle, and vacuum leaks, among other issues. Of course, it also suffers from the usual gasket leaks of any BMW engine from the era. While the engine block is solid and can handle tons of abuse and additional power without skipping a beat, the components around it tend to fail.
Later iterations of the injectors and other ancillary components improved reliability but the N54 is an engine that requires constant maintenance and can cost a fortune to maintain if you’re not DIY-inclined.
The S54 is more reliable than the N54, although both engines are high-maintenance.
On the other hand, the S54 features a more simple design without turbochargers and without a cutting-edge direct injection system. The S54 is considered the pinnacle of high-revving high-performance naturally aspirated inline-6 engines, and this helps greatly in terms of reliability. That is not to say the S54 is bulletproof; rod bearings are its weak point. VANOS is also problematic on this engine and at some point, it will need a complete rebuild or replacement.
Even with its rod-bearing issues, the S54 is a more reliable engine than the N54. Both engines can easily make it to 300k and more miles before the block dies out if you keep up with oil changes and let the engine warm-up properly, but the N54 will likely cost you more in the process.
S54 vs. N54 Sound & Exhaust Note
These two engines have completely different exhaust notes. The difference lies mostly in the N54 being a turbocharged engine that makes most of its power in the low-medium RPM range and the S54 being a naturally aspirated one that likes to be revved up to its rev limiter or 8000 rpm.
Although ranking exhaust sounds from best to worst is a very subjective matter, the vast majority of people would agree that the S54 sounds much better than the N54. The stock exhaust of the N54, combined with its twin-turbo setup, tends to suppress much of the engine’s sound note, unless extensive exhaust work and upgraded turbos are installed.
To most people, the S54 sounds much better than the N54.
There’s no doubt that there are incredible-sounding N54s out there with aftermarket exhaust systems. Turbo noises are awesome, but no straight-six engine can beat the sound note of the high-revving S54. Even in stock form with a stock exhaust, the NA S54 is a better-sounding engine than the N54.
S54 vs. N54 Engine Sound Comparison:
S54 Engine Sound:
N54 Engine Sound:
S54-powered E46 M3 vs. N54-powered E90/E92 335i
We’ve mainly been discussing the engines up until now, but what about the most iconic cars that house the S54 and the N54? We’re talking about the mythical E46 M3 compared against the early E90 335i with year models from 2007 to 2010/
The S54-powered E46 M3 has superior handling, balance, raw feel, and nimbleness. It is a lighter car with a more playful feel and a more aggressive character. After all, it’s an M3. The N54 335i can be faster in a straight line, while also being more comfortable and refined for daily cruising.
S54 vs. N54 Cost & Value
When it comes to cost, vehicles powered by the S54 tend to be more expensive than their N54 counterparts. The E46 M3 keeps appreciating in value and they are rare finds. The N54 was the powerplant of a large variety of BMWs, from the 1-series to the X6, and they are much more common and affordable.
N54-powered BMWs are easy to find and very affordable nowadays. S54-powered BMWs are hard to come by and cost more.
If you’re on a budget, a well-maintained N54 335i or 535i offers a lot of performance for the money, as long as you’re able to keep up with maintenance. A well-kept E46 M3 is a collector’s car, and will cost you a pretty penny.
No matter which one you favor, the S54 and N54 each have a significant place in BMW’s history and in the hearts of car enthusiasts worldwide.
The S54 with its high-revving, naturally aspirated character is a thrilling throwback to an era where raw, unadulterated power and the exhilarating experience of pushing an engine to its limit were the hallmarks of performance cars. Conversely, the N54 represents a leap forward into the realm of turbocharging and efficient power delivery, offering substantial performance alongside more practical daily usability.
Related article: M54 vs N52 engine comparison.