Which BMW Has the Updated B58TU2 Engine? And What's Changed
Image: BMW B58B30C Complete Engine with just 30K miles for sale at MT Auto Parts
The BMW B58 engine is the 3.0-litre turbocharged straight-six that most BMW enthusiasts consider the pick of BMW's current petrol engine range. It went into the M340i, M440i, M240i, Z4 M40i, and a handful of other models, and it has been quietly updated twice since it first arrived in 2016.
The latest version is the B58TU2, also known internally as the B58N. It arrived between 2022 and 2023, depending on the model. If you are buying a newer B58-powered BMW, working out which version you have matters, particularly if you ever need to look for a used BMW engine or specific parts. This guide keeps it simple.
The B58 Family in Plain English
The B58 has gone through three generations. The original B58 (sometimes called B58A) launched in 2016 in the F-chassis cars. Then, from 2018 to 2019, BMW updated it to what most people call the B58TU or B58D. This is the version that went into the G-chassis M Performance cars like the G20 M340i and G42 M240i. The B58TU2 (or B58N) is the third and most recent version, rolling out from 2022 onwards primarily in the larger 5, 7 Series, and X5 family.
For most owners, the practical difference between generations is not huge on the road. The B58 has always been an excellent engine. But if you need a replacement engine or specific components, the generation matters. They are not all directly interchangeable.
Which Cars Have the B58TU2 Engine?
The B58TU2 started appearing in 2022 and 2023 across the larger G-generation range. The M Performance cars (M340i, M440i, M240i) generally kept the B58TU for longer, while the luxury-oriented models (540i, 740i, X5 40i) moved to the TU2 first.
The pre-LCI G20 M340i and G42 M240i (2019 to 2022) use the B58TU, not the TU2. The LCI facelift models from 2023 onwards moved to the TU2.
Not sure which version you have? Find the 17-character VIN on the plate at the base of your windscreen and enter it at RealOEM.com. It will show your exact engine code. B58B30M1 is the TU, and B58B30M2 or B58N variants are the TU2.
What Actually Changed with the B58TU2?
The B58TU2 is a proper update rather than a minor tweak. Here is what changed, in plain terms.
48-volt mild hybrid system
This is the biggest change for most drivers. Many B58TU2 models gain a 48-volt mild hybrid system, a small electric motor integrated into the ZF 8-speed automatic gearbox. It does not give you significant electric-only range, but it assists the petrol engine at low speeds and during acceleration, making the car feel slightly quicker from low revs and improving official fuel economy figures. It also means the engine can shut off more smoothly in stop-start conditions.
Revised cylinder head and ignition
The B58TU2 has a redesigned cylinder head with revised combustion chambers and an updated ignition system. The practical effect is slightly more efficient combustion and marginally higher power in some applications. The M340i LCI, for example, produces around 386hp against the TU's 374hp.
Updated VANOS system
BMW revised the variable valve timing setup on the TU2. The changes improve response at lower engine speeds and contribute to the mild hybrid system working more effectively with the engine. You are unlikely to notice this in day-to-day driving, but it matters if you are sourcing VANOS components. TU and TU2 parts are not the same.
Emissions compliance
A chunk of the TU2's changes are about meeting stricter Euro 6d emissions standards rather than improving driver experience. Updated particulate filters and exhaust treatment systems come as part of the package. These do not affect how the engine drives, but they do affect which BMW parts are compatible.
Does It Matter Which Version You Have?
For everyday ownership, not really. All three generations of the B58 are genuinely good engines, reliable, smooth, and responsive. The TU2 is incrementally better in a few areas, but you would not feel short-changed driving a B58TU.
Where it does matter is parts. If you need a replacement B58 engine for sale, or specific components like VANOS parts, the cylinder head, or anything related to the mild hybrid system, you need to know which generation you have. Fitting a B58TU part to a B58TU2 car, or vice versa, does not always work. Always confirm using your VIN before ordering anything.
MT Auto Parts stocks genuine used B58 engines and B58 engine parts, including B58TU and B58TU2 variants, from G-generation BMW donor cars with confirmed mileage and a 30-day warranty. We break BMW only, so when you contact us about a B58 engine for sale, we confirm the exact code and generation against your car's VIN before anything is dispatched. Over 15,000 five-star reviews. 24 to 48 hours delivery in the UK. Browse at mtautoparts.com or send your registration on WhatsApp.
Frequently Asked Questions
What is the difference between the B58TU and B58TU2?
The B58TU2 adds a 48-volt mild hybrid system on most applications, a revised cylinder head with updated combustion chambers, and an improved VANOS setup. It produces marginally more power in some models. The B58TU does not have the mild hybrid system.
Which BMW models have the B58TU2 engine?
Primarily the G-generation 5, 7 Series, and X5 family from 2022 to 2023 onwards, the 540i, 740i, 840i, X5 40i, X6 40i, and X7 40i. The M340i and M440i LCI models from 2023 also moved to the TU2.
Is the B58TU2 more reliable than the earlier B58?
The B58 family in all generations has a strong reliability record. The TU2 is too new for long-term data to be definitive, but there are no documented systematic issues. The added mild hybrid components introduce more complexity, though BMW's 48V systems have generally proved dependable across other models.
Can I fit a B58TU engine into a car that had a B58TU2?
Not without significant modification. The 48-volt mild hybrid system in B58TU2 cars integrates with the gearbox and the car's electrical architecture. Swapping in an earlier B58TU would require bypassing these systems. In practice, a like-for-like replacement from a matching-generation donor car is always the right approach.
Disclaimer: The information in this article is provided for general guidance only and does not constitute professional mechanical or legal advice. Engine code designations, model fitment information, and production date references are based on publicly available BMW technical documentation and community research at the time of writing and may be subject to change. Always verify your specific engine code and parts compatibility using your vehicle's VIN before purchasing any component. MT Auto Parts accepts no liability for any loss, damage, or injury arising from reliance on information in this article. If in doubt, consult a qualified BMW specialist before making any repair or purchasing decision.
