Short answer: The S58 is BMW M's high-performance version of the B58, not a tuned B58. Both are 3.0-liter turbocharged inline-sixes with a closed-deck block, but the S58 has a bigger bore and shorter stroke, lower compression, two mono-scroll turbos instead of one twin-scroll turbo, two high-pressure fuel pumps instead of one, and a much bigger cooling and oiling system. That's why most hard parts bolted to the engine don't swap: charge pipes, downpipes, turbos, intakes, fuel pumps and heat exchangers are all engine- or chassis-specific. A short list does cross over, mostly ignition parts, some fuel-system and port-injection parts, internal engine parts sold in matching versions, and the ZF 8-speed automatic parts.
Parts and tunes in this guide are for off-road / competition use only. Not legal for use on public roads in the United States, including California.
I'm Gleb Blekher, owner of B58 Racing in Dallas, TX. My own builds are B58 cars, an M240i and a 540i. I haven't built an S58 car myself, but we sell parts for both engines, and "will this B58 part fit my M3?" comes up a lot. Here's the answer, with sources.
Which cars have a B58 and which have an S58?
| Engine | Cars (examples) | Factory output (US) |
|---|---|---|
| B58 Gen 1 (B58B30M0) | F20 M140i, F22 M240i, F30 340i, F32 440i, 2017–2019 G30 540i, G11 740i, early X3/X4 M40i | 322–355 hp depending on car |
| B58 Gen 2 (B58B30M1 / O1) | G20 M340i, G22 M440i, G42 M240i, Z4 M40i, X5/X7 40i, 2020+ 540i and 740i, Toyota GR Supra 3.0 | 335 hp (M1) or 382 hp (O1) |
| S58 (S58B30T0) | F97 X3 M, F98 X4 M, G80/G81 M3, G82/G83 M4, G87 M2 | 453–523 hp depending on car and year |
The B58 rows follow our B58 Gen 1 vs Gen 2 guide and BMW's engine codes as listed on Wikipedia. The S58 range runs from the 2023–24 G87 M2 to the M3 Competition xDrive from 2025, per BMW's releases as reported by BMWBlog. Wikipedia also lists the S58 in Alpina's B3 and B4 and in the M3 CS and M4 CSL.
Two quick traps:
- The Supra is a B58, not an S58. Every A90 GR Supra 3.0 uses a Gen 2 B58, even though some Supra and M3/M4 parts are shared (more on that below).
- An "M" badge doesn't mean S58. The M340i, M440i, M240i and X3 M40i are B58 cars. Only the full M cars listed above have the S58.
B58 vs S58 spec comparison
| B58 | S58 | |
|---|---|---|
| Displacement | 2,998 cc | 2,993 cc |
| Bore x stroke | 82.0 x 94.6 mm | 84.0 x 90.0 mm |
| Compression | 10.2:1 to 11.0:1 by version | 9.3:1 |
| Turbos | One twin-scroll | Two mono-scroll (one per three cylinders) |
| Intercooling | Water-to-air in the intake plenum | Water-to-air in the intake manifold |
| Direct injection | 200 bar (Gen 1), 350 bar (Gen 2) | 350 bar |
| High-pressure fuel pumps | One | Two |
| Block | Closed deck | Closed deck |
| Pistons | Cast aluminum | Forged Mahle |
| Redline | 7,000 rpm | 7,200 rpm |
| Cooling | Split head and block circuits on Gen 2 | Central radiator plus two side radiators, engine oil cooler, separate transmission cooler |
Sources for the table: Wikipedia's B58 and S58 entries, BMW's X3 M/X4 M launch release (bore, stroke, compression, turbos, injection, cooling, oil system), and BMWBlog's 2026 B58 vs S58 comparison (pistons, fuel pumps).
What BMW M actually changed
The S58 shares its basic architecture with the B58, and that's about it. BMWBlog's comparison puts it plainly: the S58 is "not a tuned B58," and nearly every combustion-related part was redesigned. Here's what the sources support:
- Bore and stroke. Bigger bore, shorter stroke, and a redline of 7,200 rpm instead of 7,000.
- Crank, rods and pistons. Both engines use a forged crankshaft. BMW says the S58's forged crank is light, with low rotating mass, which helps it rev to 7,200 rpm. BMWBlog reports the S58's rods come from BMW M's S63 V8 and its pistons are forged Mahle units, where the B58 uses cast pistons. BMWBlog also says the head gasket went from three layers to four.
- Block. Both are closed deck. BMW says the S58's cylinder walls have a wire-arc sprayed iron coating.
- Cylinder head. BMW says the S58 head core is 3D printed, which saves weight and lets BMW route coolant passages in ways casting can't.
- Turbos. The B58 uses a single twin-scroll turbo. The S58 uses two mono-scroll turbos, each feeding three cylinders, with an electronically controlled wastegate, per BMW.
- Fuel. The S58 runs 350-bar direct injection, the same pressure as a Gen 2 B58. The difference is that it uses two high-pressure pumps instead of one. BMWBlog says the pumps can alternate at light load and work together under hard use.
- Cooling and oil. BMW lists a central radiator with two smaller radiators beside it, an extra engine oil cooler and a separate transmission oil cooler. The S58 also has a two-chamber oil sump with a map-controlled pump, built to keep oil supply steady under hard cornering and braking.
These changes are why most fitment answers below are "no."
Parts that don't cross over
Charge pipes. A B58 has one turbo and one charge pipe. The S58 charge pipe is a Y-shaped pipe that joins both turbo outlets. A B58 pipe can't fit. See the FTP Motorsport S58 aluminum charge pipe and our S58 charge pipe install guide. Shop charge pipes.
Downpipes. The B58 has one downpipe. The S58 has two, one per turbo. Even within a brand, these are separate parts. Spool, for example, sells a B58 4.5" race downpipe and a separate S58 race downpipe for the M2, M3 and M4. More in our S58 downpipe install guide and on downpipes.
Turbos. B58 upgrade turbos are singles. S58 upgrades are twin-turbo kits or top-mount single conversions. They don't swap in either direction. Shop turbos.
Intakes and inlet pipes. With two turbos, the S58 uses its own inlet pipes and filters. B58 intakes won't fit. Shop intakes.
High-pressure fuel pumps. One pump on the B58, two on the S58, so B58 HPFP upgrades don't apply. Read the B58 fueling guide for the B58 side.
Heat exchangers and coolers. These follow the chassis, not just the engine. The CSF heat exchanger for the G80, G82 and G87 is S58-only. Shop cooling.
Oil filter housings. Billet housings are sold by engine. MMX makes one for the B58 and a different one for the S58.
Exhausts. Mid pipes, cat-backs and axle-backs are chassis-specific. Shop exhaust.
Parts that do cross over
These are the parts in our catalog whose fitment lists both engines. Always check the fitment line, because "fits both" sometimes means "sold in a B58 version and an S58 version."
Ignition
- Spark plugs (Gen 2 B58 and S58 only). The NGK 96206 is the plug BMW fits to both the Gen 2 B58 and the S58, under the same BMW part number. Gen 1 B58s use a different plug, and Toyota lists its own plug for the Supra. The Dinan iridium plug also lists B58 and S58 cars.
- Coils. The CTS Turbo ignition coil and the Dinan B-Series coil list Gen 1, Gen 2 and S58. Our spark plugs and coils guide covers gaps and change intervals.
Fuel
- S58 injectors in a Gen 2 B58. This one only goes one way. Dorch sells genuine S58 direct injectors as an upgrade for Gen 2 B58s, and says they flow about 30% more than the stock B58 injector with the correct spray pattern. They're not listed for Gen 1.
- Supra and M3/M4 fuel pump modules. DeatschWerks makes one in-tank module for the A90 Supra and the G80 M3 and G82 M4, like the dual DW420 module. Its fitment doesn't include other B58 BMWs, the M2 or the X3 M.
- Ethanol and port-injection parts. The Spool B58/S58 ethanol sensor harness, the Injector Dynamics ID1050X port injectors and the Spool handheld ethanol analyzer are sold for both engines. Shop fueling.
Engine internals (matching versions)
- The Kelford Extreme valve spring kit lists B58 and S58 cars.
- VTT carbon head gaskets and the VTT crankcase vacuum pump kit come in separate B58 and S58 versions. Pick the one for your engine. Shop engine.
Transmission (automatic cars)
Automatic B58 BMWs, the automatic Supra and automatic S58 cars all use a ZF 8-speed. The Spool billet race torque converter, the Spool 8HP oil pan and ZF LifeguardFluid 8 list both engines with the 8HP50, 8HP51 or 8HP76. Which 8HP your car has depends on the model, so check the fitment line. Shop drivetrain.
Chassis crossovers
Some parts cross over because the cars share a chassis, not an engine:
- The CSF heat exchanger and transmission cooler module fits the X3 M and X4 M and also the G01/G02 X3 and X4 M40i.
- The SPL bumpsteer tie rod ends and the P3 gauge fit the M340i, M440i and G42 M240i as well as the M2, M3 and M4.
Where to go next
The S58 starts with more power and more hardware from BMW: two turbos, two fuel pumps and the bigger cooling package. The B58 is in many more models, so its aftermarket is bigger overall. For build order, see the best B58 mods, in order or the S58 mods guide, and for known issues, B58 common problems and S58 common problems.
Not sure what fits your car? Browse all S58 parts, shop by car, or send us your VIN.
FAQ
Is the S58 just a tuned B58?
No. It shares the B58's basic architecture, but BMW M changed the bore and stroke, compression, pistons, turbos, fuel pumps, cylinder head, cooling and oiling. BMWBlog says nearly every combustion-related part was redesigned.
Do B58 parts fit an S58?
Most engine-bay hardware doesn't: charge pipes, downpipes, turbos, intakes, HPFPs and heat exchangers are all different. Ignition parts, some fuel and port-injection parts, ZF 8-speed parts, and internals sold in matching versions do cross over.
Do the B58 and S58 use the same spark plugs?
The Gen 2 B58 and the S58 both use the NGK 96206 from the factory. The Gen 1 B58 uses a different plug (NGK 94201).
Can I put S58 injectors in my B58?
In a Gen 2 B58, yes. Dorch sells genuine S58 injectors as a Gen 2 B58 upgrade with about 30% more flow. You need a tune to run them. They're not listed for Gen 1.
Does the Toyota Supra have an S58?
No. Every A90 GR Supra 3.0 has a Gen 2 B58. It does share some parts with the M3 and M4, like the DeatschWerks fuel pump modules. See our A90 Supra mods guide.
Is the S58 closed deck like the B58?
Yes. Both blocks are closed deck. BMW says the S58's closed-deck block allows higher combustion pressure and more power.
Sources
- B58 and S58 specs, versions and applications: Wikipedia, BMW B58, Wikipedia, BMW S58
- S58 bore, stroke, compression, closed deck, 3D-printed head core, turbos, 350-bar injection, cooling and oil system: BMW Group, 2020 X3 M and X4 M release
- Pistons, rods, head gasket, dual HPFPs: BMWBlog, B58 vs S58 comparison
- Crossover part fitment: manufacturer fitment as listed on each product page in our catalog