Short answer: Gen 1 is the original B58 (engine code B58B30M0), found in F-chassis cars and early G-chassis cars like the 2017–2019 540i. Gen 2 is the 2018 "technical update" or B58TU (codes B58B30M1 and B58B30O1). It's in the G20 M340i, the G42 M240i, the X5 40i, the Z4 M40i and every Toyota GR Supra 3.0. The biggest practical differences are the fuel system (200 bar vs 350 bar), the timing chain, cooling and the charge pipe. Those decide which parts fit.
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. Both of my own B58 builds were Gen 1, and one of them, a G30 540i, is exactly the kind of car that trips people up. Here's how to get it right before you order parts.
Which B58 do I have? Quick model guide
| Car | Gen 1 (B58B30M0) | Gen 2 (B58TU: M1 / O1) |
|---|---|---|
| F22/F23 M240i | 2016–2021 | — |
| F20/F21 M140i | 2016–2019 | — |
| F30/F31/F34 340i, F32/F33/F36 440i | All years | — |
| G30/G31 540i | 2017–2019 | 2020+ (until the G60) |
| G11/G12 740i | 2016–2019 | 2020+ |
| G01 X3 M40i, G02 X4 M40i | Early cars (2018–2019) | 2020+ |
| G20 M340i, G22/G23/G26 M440i | — | Yes (B58B30O1) |
| G42 M240i | — | Yes (B58B30O1) |
| G05 X5 / G07 X7 40i, G14–G16 840i | — | Yes |
| G29 Z4 M40i | — | Yes |
| Toyota GR Supra A90 3.0 | — | Yes (all) |
This table follows BMW's engine-code assignments as listed on Wikipedia. Changeover dates vary by market and build month. Treat model year as a starting point, not proof.
How to confirm
- Check the engine code. Run your VIN through a BMW VIN decoder or look at your build sheet. B58B30M0 is Gen 1. B58B30M1 or B58B30O1 is Gen 2. B58B30M2 is the newer "Gen 3" (TU2).
- Look at the throttle body. One parts maker notes Gen 1 uses a three-bolt throttle body flange and Gen 2 uses a two-bolt design. That's why charge pipes don't swap.
- For tuning, check the DME date too. Whether your DME needs a bench unlock depends on its software and production date, not just the generation.
What BMW changed in the 2018 update
Per BMW's published changes and parts makers:
- Fuel system: pressure went up about 75%, from a 200-bar system to 350 bar, with a new HPFP and new injectors.
- Timing chain: the two-piece chain became a single chain, with matching changes to the VANOS gears.
- Cooling: split cooling, with separate circuits for the head and the block, managed by a heat management module.
- Crankshaft and block: a lighter forged crank and optimized crankcase walls.
- Exhaust side: Gen 2 added a particulate filter (OPF) on the mid-pipe in markets that require one. Some mid-output Gen 2 engines (often called B58C, "2-port") moved the exhaust manifold into the head. High-output engines (B58D, "6-port") use a separate manifold.
- Belt drive and ECU: a shorter belt layout and a different DME per version.
What did not change
Two things people often get wrong:
- Closed deck. The B58 block is closed-deck from the start. It's not a Gen 2 upgrade.
- Intercooler layout. Both generations use a water-to-air intercooler built into the intake plenum, cooled by a front heat exchanger. The front heat exchanger part differs by chassis, not just by generation.
Gen 1 vs Gen 2 comparison table
| Gen 1 (B58A, B58B30M0) | Gen 2 (B58TU, B58B30M1 / O1) | |
|---|---|---|
| Years | About 2015–2019 (M240i to 2021) | 2018/2019 onward |
| Output (stock) | 322–355 hp depending on car | 335 hp (M1) or 382 hp (O1) |
| Fuel pressure | 200 bar | 350 bar |
| Timing chain | Two-piece | Single chain |
| Cooling | Conventional | Split cooling |
| Exhaust manifold | Separate | Integrated (2-port) or separate (6-port) |
| Throttle body flange | 3-bolt | 2-bolt |
| Block | Closed deck | Closed deck |
| Intercooler | Water-to-air in plenum | Water-to-air in plenum |
| Stock HPFP limit (estimate) | Around 450 whp on 93 | Around 520–540 whp on pump gas |
The last row is an estimate from BMWTuning.co, not our dyno data.
Why it matters for parts fitment
Charge pipes: not interchangeable
Gen 1 and Gen 2 charge pipes do not swap. The VRSF, FTP Motorsport and BMS Elite Gen 1 pipes are for B58A only. For Gen 2, look at Mishimoto, CTS Turbo, do88 and the BMS Elite B58TU pipe. Shop charge pipes.
Fuel pumps and injectors: generation-specific
Gen 1 and Gen 2 pumps are different parts. Gen 1 options include the Dorch Engineering DS25, Spool FX-150 and Precision Raceworks Gauntlet. Gen 2 options include the Dorch Engineering Gen 2 DS25 (350 bar). Injector upgrades are also split by generation. Shop fueling.
Turbos: generation- and head-specific
Upgrade turbos come in Gen 1, Gen 2 2-port and 6-port versions. Pure Turbos says its Gen 2 2-port kits do not fit Gen 1, Gen 3 or 6-port engines. Check your head type first. Forum reports say the 2020 Supra is 2-port and 2021+ is 6-port, but confirm on your car.
Downpipes: often shared
Many downpipes, like the SPDZ1 True 4.5", list Gen 1, Gen 2 and Supra fitment. Others are chassis-specific, like the VRSF G-series and F-series pipes. Shop downpipes.
Cooling, plugs and maintenance parts
- Heat exchangers: CSF makes separate Gen 1 F-series and Gen 2/Supra units. Shop cooling.
- Plugs: NGK 94201 for Gen 1; NGK 96206 for Gen 2 and Supra.
- Valve cover gaskets, thermostats, timing chain kits: split by generation.
Parts that fit both
- B58 Racing Silicone Inlet Pipe (resonator delete) fits Gen 1 and Gen 2. See it here. G30 note below.
- ProRam B58 air filter fits the stock airbox on all B58s. More in intakes.
- Tuning: the bootmod3 B58 license covers Gen 1 and Gen 2 BMWs. The Supra uses its own license. bootmod3 B58 tune.
Still unsure which parts go together? Browse our stage kits, and check the fitment line on each part.
What about Gen 3?
From 2022, BMW started rolling out the B58B30M2, often called Gen 3 or TU2. It's in cars like the G70 740i, the 2024+ G60 540i and newer X5/X7 40i models. It adds port injection alongside direct injection. Many Gen 1/Gen 2 parts do not fit Gen 3. Some brands make separate Gen 3 tuners, like the Burger Motorsports Gen 3 JB4.
From our builds
My M240ix (F22) was Gen 1. That's normal for that car; the F22 M240i kept the Gen 1 engine through 2021.
My 2017 540i (G30) is the one to learn from. It's a G-chassis car, but it has the Gen 1 engine. If you shop by "G-series" alone, you'll order Gen 2 parts that won't fit. Its fuel pump upgrade is the Gen 1 version of the Dorch Stage 2 HPFP. It also runs a downpipe, bootmod3 (Stage 2+ OTS map on E50) and an xHP transmission tune. It runs low-9-second 60–130 on the stock turbo.
One more G30 lesson: the G30 has extra air baffling. In our experience, the silicone inlet pipe can trigger an air-leak code on a G30 unless your tuner codes it out.
Ready to build? See the best B58 mods, in order, and pick a platform with our bootmod3 vs MHD vs JB4 guide.
FAQ
Is the 2017–2019 540i Gen 1 or Gen 2?
Gen 1. BMW lists the 2017–2019 G30/G31 540i with the B58B30M0. The 2020+ 540i moved to Gen 2.
Is the Gen 2 B58 stronger than Gen 1?
The fuel system is stronger: 350 bar vs 200 bar. Both use a closed-deck block. Gen 2 has more headroom on the stock fuel pump.
Do Gen 1 charge pipes fit Gen 2?
No. The throttle body flange is different. Buy the pipe made for your generation.
Are all Supras Gen 2?
Yes, every A90 Supra 3.0 uses a Gen 2 (B58TU) engine. The 2020 cars made 335 hp; 2021+ cars made 382 hp. Head type (2-port or 6-port) matters for turbo upgrades.
Sources
- Engine codes, outputs, applications and 2018 update changes: Wikipedia, BMW B58
- B58TU changes (timing chain, split cooling, crank, manifold variants): Bimmerworld, B46TU/B58TU differences
- 200 vs 350 bar and stock HPFP estimates: BMWTuning.co, B58 HPFP upgrade
- Charge pipe throttle body flange and Gen 1-only fitment: OneFastShop Gen 1 charge pipe, FTP Motorsport via Turner
- Pure Turbos Gen 2 2-port fitment: Turner Motorsport listing
- Supra 2-port vs 6-port (forum report): SupraMKV forum
- Gen 3 port injection: Dinan, Gen 3 B58
- DME unlock requirements: MHD Super License for B58
- bootmod3 license coverage: Ort Motorsport, bootmod3 B58