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BMW S68B44 Engine - Replacement Cost, Problems & CompatibilityProblems & Compatibility
The all-new 4.4-litre twin-turbo V8 with 48V mild-hybrid assistance, powering BMW's latest-generation M Performance models including the G90 M5, G99 M5 Touring, and XM, with estimated 2025 UK replacement requests of 150-200 .
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
Used from
£8,000
Reconditioned from
£12,000
Rebuilt from
£16,000
GB
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Key Specs
BMW S68B44 - Specifications at a Glance
Engine Code
S68B44 (S68B44B)
Fuel
Petrol
Configuration
4.4L twin-turbo V8, cross-bank exhaust manifolds, hot-vee layout, 48V mild-hybrid integrated starter-generator (ISG), direct injection, Valvetronic, double VANOS
Power Output(s)
557-577 hp (410-425 kW) in M5; 644 hp (474 kW) in XM Label; 738 Nm torque; hybrid boost up to 12 hp
Years Produced
2022-present
UK Models Fitted
4 BMW M models - full list in Compatibility below
2025 UK Replacement Requests
Estimated 150-200 (new engine, data not yet in proprietary file)
Replaced
S63B44T4
Replaced By
None (current production)
Most Common Failure
Early reports: cooling system complexity; oil pump chain tensioner (monitor)
Reconditioned Price Range
£12,000-£18,000 supply-only
Vetted UK specialists for S68B44 replacements
Minimum 12-month warranty on reconditioned and rebuilt options
Fitted To
Which BMW M Models Use the S68B44-
TAG: Fitted To
| Model | Generation/Chassis | Badge(s) | Years | Link |
|---|---|---|---|---|
 BMW XM | G09 | XM (base), XM Label | 2022-present | |
| BMW M5 | G90 | M5 (sedan) | 2024-present | |
| BMW M5 Touring | G99 | M5 Touring | 2024-present | |
| BMW X5 M | G95 | X5 M (future) | Expected 2025+ |
02
BMW M5
03
BMW M5 Touring
04
BMW X5 M
CROSS-BRAND
S68B44 is documented across 4 BMW applications spanning BMW XM, BMW M5, BMW M5 Touring, BMW X5 M. Registration lookup confirms the exact suffix before quotes are sent.
Not sure which engine your car has?
Not sure which M engine your car has- Enter your registration above - we'll confirm your exact S68B44 fitment before any quotes are sent.
Prices
BMW S68B44 Engine Replacement Cost (UK)
Condition | Supply Only | Fitted (Independent Specialist) | Typical Warranty |
|---|---|---|---|
Used | £8,000-£12,000 | £9,040-£13,360 | 3-6 months |
Reconditioned | £12,000-£18,000 | £13,040-£19,360 | 12-24 months |
Rebuilt | £16,000-£22,000 | £17,040-£23,360 | 12-24 months |
All prices are as S68B44 data is not yet in the proprietary file. Fitted = supply price + 18-24 hours at £65/hr independent labour.
Labour Guide
Fitting an S68B44 typically takes 18-24 hours at £65-£85/hr (independent M specialist) - the hybrid system adds complexity; confirm exact labour when comparing quotes.
Price Factors
What genuinely moves the price for the S68B44 is the engine's low production volume and the integrated 48V mild-hybrid system - only a handful of UK specialists are familiar with this new architecture. A unit with documented service history and low mileage commands a premium. See our full reconditioned engine cost guide.
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Common Problems
BMW S68B44 Engine Problems - What Actually Fails
Every engine has its weak points. Here are the known issues with the S68B44, based on real-world data and verified failure patterns.
Verified issue focus: Early reports: cooling system complexity; oil pump chain tensioner (monitor).
1. Cooling System Complexity - multiple circuits and electric water pumps
1. Cooling System Complexity - multiple circuits and electric water pumps
Typical onset:
Unknown (engine is relatively new; early data limited)
What happens:
The S68B44 features a split cooling system with separate circuits for the engine, turbos, and hybrid components, plus electric water pumps. Early forum reports indicate potential for leaks at plastic connections and pump failures, though long-term data is not yet available.
Repair vs replace:
Cooling system components are individually replaceable, but access is difficult. Preventative inspection at 40k miles is recommended.
Read more about this issue
2. Oil Pump Chain Tensioner - potential fatigue
2. Oil Pump Chain Tensioner - potential fatigue
Typical onset:
Unknown (speculative, based on S63 history)
What happens:
The S68B44 carries forward some design elements from the S63, including a chain-driven oil pump. The tensioner may wear over time, causing oil pressure drops. This is speculative at this stage - the S68 has revised components, but owners should monitor oil pressure and engine noise.
Repair vs replace:
If oil pressure drops, immediate investigation is required. Tensioner replacement is a standalone repair if caught early; failure can lead to bottom-end damage.
Read more about this issue
The S68B44 is too new to have a well-established failure profile. Early indicators suggest it is more robust than the S63 family, with the 48V system adding complexity but also enabling higher efficiency. All production years are similar; 2024+ models may have small revisions.
Compare rebuilt S68B44 prices with the latest updates addressed
Engine Variants
How to Confirm You Have the S68B44
The S68B44 is BMW's latest high-performance V8, introduced in 2022. It is the first M V8 to feature a 48V mild-hybrid integrated starter-generator (ISG) located between the engine and transmission, enabling additional torque and smoother start-stop. Where to find the engine code: - On the engine block - a stamped plate near the left bank (viewed from the driver's seat) - On the V5C registration document - under engine number - Via a BMW VIN decoder - the 7th and 8th characters of the VIN identify the engine family Commonly confused codes: - S63B44T4 - the previous M V8, without mild-hybrid and with older fuel/ignition systems; not interchangeable - S63TU - the S63 family page; some older XM prototypes may have used S63 variants, but production XMs use S68 - N63B44B - the non-M version of the N63 V8, not to be confused with S68
Not sure which M V8 your car has- Enter your registration above - we'll confirm your exact fitment before any quotes are sent.
Easily Confused
S63B44T4
the final evolution of BMW's previous M V8, found in the F90 M5 CS and later M8 variants. The S63T4 produced up to 635 hp but lacked the S68's 48V mild-hybrid system; the S68's integrated starter-generator and revised hot-vee design represent a significant step forward in both power delivery and efficiency. [S63B44T4 Engine - /bmw/s63b44t4-engine/]
Alternative / Next-Gen Code
S63TU
the family page covering the entire S63 generation (T0-T4). The S68 is not part of the S63 family - it's a new engine with a different architecture and hybrid integration - but the S63TU page is useful for understanding the lineage. [S63TU Engine - /bmw/s63tu-engine/]
Confirm the exact S68B44 fitment
Not sure which M V8 your car has- Enter your registration above - we'll confirm your exact fitment before any quotes are sent.
Buying Guide
Buying a Replacement S68B44 - What to Choose
Choosing the right replacement route depends on your budget, risk tolerance, and ownership goals. Here's a breakdown of your options.
Used:
A used S68B44 is only viable if you can obtain a complete unit with its hybrid components (ISG, wiring, cooling) from a low-mileage, accident-damaged car. Given the engine's recent introduction, used units are extremely rare and command high prices (£8,000-£12,000). Verify that the 48V system and all sensors are included - missing components will be costly to source. Used engines
Reconditioned:
A reconditioned S68B44 is the most practical choice for owners of XM or new M5 models, provided the specialist has access to BMW's latest diagnostic tools and software. A proper recon will include new timing chain components, cooling system refresh, and hybrid system calibration. Expect £12,000-£18,000 with 12-24 months warranty - but availability is currently limited. Reconditioned engines
Rebuilt:
A full S68B44 rebuild is a specialist undertaking due to the hybrid system. This is only justified for extreme high-performance builds or warranty replacement. Costs are likely to exceed £16,000-£22,000. As of 2025, very few UK workshops have experience rebuilding this engine. Rebuilt engines
Supply & Fit Line:
Our vetted UK BMW M specialists are now gaining experience with the S68 platform - supply-only or full supply-and-fit available, with warranty on reconditioned units. Supply and fit
Vehicle Value Note:
The S68B44 sits in cars worth £80,000-£200,000+ (XM, new M5). A reconditioned S68B44 at £12,000-£18,000 represents 10-20% of vehicle value - well within safe territory. However, because the engine is so new, replacement parts and expertise are scarce, which may inflate actual costs. Consider the overall availability of specialist support before committing.
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Related Engines
Engines Related to the BMW S68B44
Explore engines that are closely related to the BMW S68B44, including its predecessor, successor, and key family variants.
Predecessor
S63B44T4
the final evolution of BMW's previous M V8, found in the F90 M5 CS and later M8 variants. The S63T4 produced up to 635 hp but lacked the S68's 48V mild-hybrid system; the S68's integrated starter-generator and revised hot-vee design represent a significant step forward in both power delivery and efficiency. [S63B44T4 Engine - /bmw/s63b44t4-engine/]
Successor
None
the S68B44 is BMW M's current V8 flagship, with no announced replacement as of 2025.
Sibling
S63B44T4
the previous-generation M V8 shares some architecture with the S68 but is non-hybrid. If you own a pre-2022 M5 or M8, this is the page you need - the S68 is a distinct engine with hybrid components. [S63B44T4 Engine - /bmw/s63b44t4-engine/]
Sibling
S63TU
the family page covering the entire S63 generation (T0-T4). The S68 is not part of the S63 family - it's a new engine with a different architecture and hybrid integration - but the S63TU page is useful for understanding the lineage. [S63TU Engine - /bmw/s63tu-engine/]
FAQ
BMW S68B44Frequently Asked Questions
Question 1How much does an S68B44 engine replacement cost in the UK-
A reconditioned S68B44 supply-only is estimated at £12,000-£18,000, with fitted prices from £13,040 to £19,360 depending on labour and the hybrid system integration. Used units are rare and cost £8,000-£12,000 if available. Rebuilt units may exceed £16,000-£22,000. Warranty is typically 12-24 months on reconditioned/rebuilt units.
- Used units are rare and cost £8,000-£12,000 if available.
- Rebuilt units may exceed £16,000-£22,000.
- Warranty is typically 12-24 months on reconditioned/rebuilt units.
Question 2What are the common problems with the S68B44 engine-
The S68B44 is too new to have a well-established failure profile. Early reports indicate potential cooling system complexity and oil pump chain tensioner wear, but long-term data is not yet available. The split cooling system with electric pumps is a new design. Early S63-based issues may carry over to some components. 48V hybrid system adds complexity but is generally reliable.
- The split cooling system with electric pumps is a new design.
- Early S63-based issues may carry over to some components.
- 48V hybrid system adds complexity but is generally reliable.
Question 3Which BMW M models have the S68B44 engine-
The S68B44 powers the BMW XM (G09), new G90 M5, G99 M5 Touring, and will power future X5 M and X6 M variants from 2025 onwards. It replaced the S63 family from 2022. The 48V mild-hybrid system is integrated between the engine and transmission.
- It replaced the S63 family from 2022.
- The 48V mild-hybrid system is integrated between the engine and transmission.
Question 4Should I buy a used or reconditioned S68B44-
A reconditioned S68B44 is the safer choice, provided the specialist has BMW's latest diagnostic tools and experience with the hybrid system. Used units are scarce and may lack hybrid components. Reconditioning addresses the engine's internal wear while preserving the hybrid calibration. For XM owners, reconditioned is the only practical option.
- Used units are scarce and may lack hybrid components.
- Reconditioning addresses the engine's internal wear while preserving the hybrid calibration.
- For XM owners, reconditioned is the only practical option.
Question 5How do I know if my car has the S68B44 and not another V8 variant-
The engine code is stamped on the block (left bank) and listed on your V5C or via a BMW VIN decoder. It is commonly confused with S63B44T4 and older S63 variants. The presence of 48V hybrid system and the G09/G90 chassis codes confirm S68. Fitting a non-hybrid S63 engine will not work - the hybrid system is integrated.
- It is commonly confused with S63B44T4 and older S63 variants.
- The presence of 48V hybrid system and the G09/G90 chassis codes confirm S68.
- Fitting a non-hybrid S63 engine will not work - the hybrid system is integrated.
Question 6Is the S68B44 a reliable engine-
The S68B44 is too new to have a definitive reliability reputation - early data suggests it is BMW's most advanced V8, but complexity is high. The 48V mild-hybrid system adds components that may require maintenance. The hot-vee cooling and turbo setup is similar to S63, but revised. Expect higher ownership costs due to specialist parts and labour.
- The 48V mild-hybrid system adds components that may require maintenance.
- The hot-vee cooling and turbo setup is similar to S63, but revised.
- Expect higher ownership costs due to specialist parts and labour.
Compare BMW S68B44 Engine Prices Today
Vetted UK M specialists with growing experience on the S68B44 and its 48V hybrid system Minimum 12-month warranty on every reconditioned and rebuilt S68B44 Nationwide delivery - supply-only or full supply & fit No-obligation comparison tailored to your exact engine code and hybrid system configuration. Enter your registration and we'll confirm your S68B44 fitment before any quotes are sent. With reconditioned S68B44 units from around £12,000, comparing takes two minutes - and given the newness of this engine, finding the right specialist is essential.
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Minimum 12-Month Warranty
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