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BMW B58 Gen 1 vs Gen 2 – Full Technical Differences Explained
When BMW introduced the B58 engine in 2015, it quickly gained a reputation as one of the brand’s best inline-six engines—powerful, smooth, and reliable with huge tuning potential. Over the years, BMW updated it, introducing the B58 Gen 2 in 2019.
While both generations share the same DNA, BMW made important refinements in performance, efficiency, and design.
While both generations share the same DNA, BMW made important refinements in performance, efficiency, and design.
1. Engine Block & Internal Design
2. Turbocharger & Cooling System
3. Fuel System & Emissions Technology
4. Power & Performance Output
5. Tuning Potential
6. Applications & Models
Final Verdict: Which One is Better?Both B58 generations are excellent, but:
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- B58 Gen 1
- Introduced in 2015.
- Features a closed-deck aluminum block for strength.
- Built with a forged crankshaft and strong internals, giving it excellent durability for tuning.
- Compression ratio: around 11.0:1 (varies slightly by model).
- B58 Gen 2
- Released around 2019 with upgrades for emissions and efficiency.
- Still closed-deck but optimized for reduced internal friction.
- Compression ratio increased to 11.2:1, improving fuel efficiency and throttle response.
- Stronger piston rings and redesigned cooling passages.
2. Turbocharger & Cooling System
- Gen 1 Turbo Setup
- Single twin-scroll turbocharger.
- Slightly smaller compressor wheel, spooling up quickly for daily drivability.
- Adequate cooling with air-to-liquid intercooler integrated into the intake manifold.
- Gen 2 Turbo Setup
- Larger twin-scroll turbo with better flow capacity.
- Supports higher peak power while maintaining low-end torque.
- Improved cooling system: refined intercooler design and more efficient heat management.
3. Fuel System & Emissions Technology
- B58 Gen 1
- 2nd-generation direct injection system.
- Meets Euro 6 standards but without the latest particulate filters.
- Slightly less precise fuel atomization compared to newer setups.
- B58 Gen 2
- Upgraded fuel injection system with higher pressure.
- Equipped with Gasoline Particulate Filter (GPF/OPF) in many markets.
- More eco-friendly without sacrificing performance.
4. Power & Performance Output
- Typical B58 Gen 1 (340i, 440i, etc.)
- Stock output: 322–355 hp and around 450 Nm torque.
- Real-world dyno often shows higher figures than BMW claims.
- Typical B58 Gen 2 (Z4 M40i, Supra, M340i, etc.)
- Stock output: 382–388 hp and 500 Nm torque.
- Much stronger mid-range and top-end performance.
5. Tuning Potential
- Gen 1 Tuning
- Known for hitting 450–500 hp on stock turbo with bolt-ons and a proper tune.
- Excellent aftermarket support worldwide.
- Very reliable when tuned moderately.
- Gen 2 Tuning
- Even more headroom thanks to larger turbo and stronger internals.
- Capable of 500+ hp with bolt-ons and tune.
- With hybrid or upgraded turbos, 600–700 hp builds are achievable.
6. Applications & Models
- B58 Gen 1
- 2016–2019 BMW 340i, 440i, 540i, 740i, X3/X4 M40i (early versions), Toyota Supra (early A90).
- B58 Gen 2
- 2019+ BMW Z4 M40i, M340i, M440i, M540i, X3 M40i, X4 M40i, updated Supra (2021+).
Final Verdict: Which One is Better?Both B58 generations are excellent, but:
- Gen 1 is perfect if you want a strong, proven, and cost-effective engine with huge tuning potential.
- Gen 2 offers more refinement, better efficiency, and higher stock power output—ideal if you’re after the latest technology and plan on extracting maximum performance.
Ready to Master BMW Tuning?If you want to take your knowledge and tuning skills to the next level, we highly recommend joining the BMW Course Account. You’ll gain access to detailed training, ECU tuning resources, and real-world repair guides trusted by professionals.
👉 Join BMW Course Account
This is the ultimate way to unlock the full power of your BMW and stay ahead in the automotive tuning game.
1 Comments
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