Since its debut in 2015, the BMW B58 engine has solidified itself as one of the most impressive turbocharged inline-sixes ever produced. Initially introduced as part of BMW’s modular engine family, the B58 replaced the N55 and immediately gained recognition for its power output, thermal efficiency, reliability, and tuning flexibility. But what truly sets the B58 apart is how it has evolved over time — through a series of technical updates known as B58TU (Technical Update) and B58TU2, introduced across multiple model generations.
In this article, we explore the full technical evolution of the B58 engine, comparing B58 vs B58TU vs B58TU2. If you're a performance builder, tuner, or prospective BMW owner, this guide will help you understand the differences between each generation and how they impact performance, tuning, and real-world drivability.
🧬 B58 Gen 1: The Original (B58B30M0)
Production Range: 2015–2018
Vehicles:
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F30 340i / F32 440i
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G30 540i (early)
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G11/G12 740i (early)
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G01 X3 M40i (early)
🔧 Key Technical Specs:
| Component | B58 Gen 1 (B58B30M0) |
|---|---|
| Block Design | Closed-deck aluminum |
| Bore x Stroke | 82.0 mm × 94.6 mm |
| Displacement | 2,998 cc |
| Compression Ratio | 11.0:1 |
| Fuel System | Direct injection (200 bar) |
| Turbocharger | BorgWarner twin-scroll, integrated WG actuator |
| Charge Cooling | Integrated water-to-air intercooler (in intake manifold) |
| Max Factory Output | ~322–340 hp / ~450 Nm (varies by market) |
🔍 Technical Overview:
The Gen 1 B58 was a major leap forward from the N55. The closed-deck block, integrated charge cooler, and high thermal efficiency (up to 40%) set a new standard in the segment. Factory internals (forged crankshaft, cast aluminum pistons, and reinforced rods) provided the robustness needed for tuning well beyond factory figures — with 400–450+ hp achievable on stock hardware.
🔁 B58TU: The First Technical Update (B58B30O1)
Production Range: 2019–2022
Vehicles:
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G20 M340i
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G29 Z4 M40i
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A90 GR Supra (3.0, post-2021 update)
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G30 540i (LCI)
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G01 X3 M40i (LCI)
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G02 X4 M40i
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G05 X5 40i
⚙️ What Changed in B58TU:
| Component | B58TU (B58B30O1) Improvements |
|---|---|
| Fuel Pressure | Increased from 200 to 350 bar |
| Turbocharger | Revised twin-scroll with lighter turbine wheel |
| Charge Cooling | Larger dual-pass integrated charge cooler |
| Exhaust Valve Sizing | Enlarged for improved flow and response |
| Crankcase Ventilation | Reworked PCV and breather system |
| ECU | Bosch MG1 with more robust torque management |
| Oil & Coolant Routing | Redesigned for thermal efficiency |
| Factory Output (M340i) | 382 hp / 500 Nm (North America spec) |
🛠️ Impact on Performance & Tuning:
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Increased boost headroom, more responsive turbo spool
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More efficient combustion due to better valve sizing and fueling
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Cooler intake temps under sustained load
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Factory flex-fuel compatibility in some markets
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Tuning ceiling raised to ~550–600 hp on stock turbo with ethanol + bolt-ons
The B58TU solidified the engine’s place in modern tuning — becoming a favorite for hybrid turbo conversions, flex-fuel builds, and even road-race applications. The DME (MG1) introduced tougher encryption, but flashing support matured rapidly through MHD, BM3, and Ecutek.
🔁 B58TU2: The Second Update (B58B30M2 / 2022–Present)
Production Range: 2022–Present
Vehicles:
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G87 M2
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G20 LCI M340i (2022+)
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G42 M240i xDrive
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G30 540i (late LCI)
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G70 740i
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G05 X5 LCI (2023+)
⚙️ B58TU2 — What’s New:
| Component | B58TU2 (B58B30M2) Enhancements |
|---|---|
| Turbo System | Revised housing, faster spooling twin-scroll |
| E-Valve Integration | Enhanced turbo bypass and WG control |
| Fuel Injection | Optimized injector angle for cleaner burn |
| Emissions | EU7/US EPA Tier 3 compatibility |
| Exhaust Architecture | Integrated OPF (gas particulate filter) in some markets |
| Cooling Logic | More aggressive thermal management curves |
| Factory Output (M2) | 453 hp / 550 Nm (varies by application) |
🔬 Technical Summary:
B58TU2 was less about raw performance increase and more about refinement, emissions compliance, and future-proofing. That said, it still brought:
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Better low-end response
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Stronger high-RPM pull
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Improved fuel atomization and combustion chamber efficiency
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Next-gen ECU calibration with enhanced adaptive logic
Despite stricter emissions constraints, BMW still delivered 450+ hp in the G87 M2 — showing that the B58TU2 is equally capable under pressure. Tuning tools have kept pace, though ECU unlocking for TU2 requires bench/boot methods or dealer flash licensing.
📊 Comparative Chart: B58 Gen 1 vs TU vs TU2
| Feature | B58 (Gen 1) | B58TU (Gen 2) | B58TU2 (Gen 3) |
|---|---|---|---|
| Max Fuel Pressure | 200 bar | 350 bar | 350 bar |
| Charge Cooler Design | Single-pass | Dual-pass | Dual-pass, enhanced |
| Turbocharger | Gen 1 twin-scroll | Revised twin-scroll | Further optimized |
| Intake Valve Sizing | Standard | Enlarged | Revised angle/spray |
| Emissions Focus | EU6 | EU6.2 / SULEV | EU7-ready (OPF) |
| Peak Output (Factory) | ~340 hp | 382 hp (M340i) | 453 hp (G87 M2) |
| Tuning Limit (Stock Turbo) | ~480–500 hp | ~550–600 hp | ~550–620 hp (est.) |
| Fueling Mods Required (E85) | Yes | Sometimes (Flex fuel friendly) | Yes (TU2-specific support) |
🏁 What This Means for Tuners
If you’re planning to modify a B58-powered car, the version of the engine you have will affect:
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Turbo sizing and spool dynamics
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Flex-fuel support and fueling limitations
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Cooling upgrade requirements
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ECU tuning access (boot vs OBD unlock)
At RPM Performance, we’ve developed reliable tuning packages for B58 Gen 1, TU, and TU2 platforms, offering:
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Stage 1–3 calibrations
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Hybrid turbo upgrades
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Flex-fuel conversions
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Transmission tuning (ZF8HP)
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Thermal management mods
Whether you're running a Z4 M40i, G20 M340i, A90 Supra, or G87 M2, understanding your specific B58 variant is essential for a safe and effective build strategy.
✅ Final Thoughts: The B58 Keeps Getting Better
The evolution from B58 Gen 1 → TU → TU2 reflects BMW’s commitment to refining its most important performance engine of the last decade. Unlike most modern turbo engines that prioritize efficiency at the expense of tuneability, the B58 continues to support high-output, enthusiast-built setups while meeting modern standards.
Each generation builds upon the last — with the B58TU introducing meaningful performance gains and B58TU2 focusing on emissions compliance and refinement without sacrificing output. No matter the version, the B58 remains one of the most tuneable and durable inline-six engines available today.
If you've got a B58, and you want to get the best out of the platform, then please reach out to us and we'll sort you out!