BMW X4 G02SUV Coupé2018–2025
Every engine fitted to the X4 G02 sports activity coupé — from the B48 four-cylinder petrol and B47 diesel to the B58 turbo six and the S58-powered X4 M Competition.
Real UK replacement costs and honest reliability data for BMW's second-generation coupé-SUV.
Backed by real UK enquiries [BMW-VERIFIED].
Engine Database
Every engine fitted to the X4 G02 specifically — including the full range of four-cylinder B48 petrol and B47 diesel engines, the B58 six-cylinder petrol, the S58-powered X4 M, and European-market diesel six-cylinders.
Overview
The G02 is the second generation of the BMW X4, a compact luxury crossover SUV produced from February 2018 to November 2025. Built on the CLAR platform shared with the X3 G01, it succeeded the F26 and introduced a stiffer body structure, improved dynamics, and a broader engine lineup. The engine range includes B48 four-cylinder petrols and B47 diesels, B58 six-cylinder petrols, B57 six-cylinder diesels (Europe), and the S58-powered X4 M.
A 2021 Life Cycle Impulse brought mild-hybrid technology and revised styling. The X4 G02 was discontinued in November 2025 with no direct successor planned.
Key Facts
Market Intelligence
The X4 nameplate generated significant UK engine enquiries in 2025 [BMW-VERIFIED], with demand concentrated on the B48-powered xDrive20i and B58-powered M40i models based on market patterns.
04Best & Worst Engines
Best Value
B48B20O1 (xDrive30i)
“The 2.0-litre B48 delivers 245–249 bhp — more than enough for everyday driving — with excellent fuel economy and lower running costs than the six-cylinder. It's the sensible choice that doesn't feel sensible.”
Who it's for: buyers who want modern turbo performance with sensible running costs.
Highest Risk
S58B30A (X4 M / X4 M Competition)
“The S58 is an engineering masterpiece — a twin-turbo straight-six based on the B58 with a closed-deck crankcase and 350-bar fuel injection. But it's complex, high-strung, and expensive to maintain. Crank hub issues, cooling system failures, and high running costs are well-documented concerns.”
Who it's for: buyers with deep pockets who want the ultimate X4 — and are prepared for the running costs.
Most Expensive Failure
S58B30A (X4 M Competition)
“A full S58 engine replacement can exceed £11,000. Crank hub failure is catastrophic and requires an engine-out rebuild. Cooling system leaks and high-pressure fuel system issues are also costly. The X4 M is a performance bargain used — but the maintenance bills are M-car levels.”
Who it's for: buyers who understand that M-car ownership comes with M-car costs.
Most Overlooked
B57D30O1 (xDrive30d)
“The six-cylinder diesel is often overlooked in favour of the M40i, but it delivers 265 bhp of effortless torque with genuine 40+ mpg economy. It's the thinking buyer's choice — refined, powerful, and efficient. Not available in all markets, but a gem where it is.”
Who it's for: buyers who want six-cylinder refinement with diesel economy.
Best Value
B48B20O1
(xDrive30i)
“The 2.0-litre B48 delivers 245–249 bhp — more than enough for everyday driving — with excellent fuel economy and lower running costs than the six-cylinder. It's the sensible choice that doesn't feel sensible.”
Who it's for: buyers who want modern turbo performance with sensible running costs.
Highest Risk
S58B30A
(X4 M / X4 M Competition)
“The S58 is an engineering masterpiece — a twin-turbo straight-six based on the B58 with a closed-deck crankcase and 350-bar fuel injection. But it's complex, high-strung, and expensive to maintain. Crank hub issues, cooling system failures, and high running costs are well-documented concerns.”
Who it's for: buyers with deep pockets who want the ultimate X4 — and are prepared for the running costs.
Most Expensive Failure
S58B30A
(X4 M Competition)
“A full S58 engine replacement can exceed £11,000. Crank hub failure is catastrophic and requires an engine-out rebuild. Cooling system leaks and high-pressure fuel system issues are also costly. The X4 M is a performance bargain used — but the maintenance bills are M-car levels.”
Who it's for: buyers who understand that M-car ownership comes with M-car costs.
Most Overlooked
B57D30O1 (xDrive30d)
“The six-cylinder diesel is often overlooked in favour of the M40i, but it delivers 265 bhp of effortless torque with genuine 40+ mpg economy. It's the thinking buyer's choice — refined, powerful, and efficient. Not available in all markets, but a gem where it is.”
Who it's for: buyers who want six-cylinder refinement with diesel economy.
Engine
Typical Mileage
Common Major Failure
Repair Cost (Specialist)
Replacement Cost (Recon)
Ownership Verdict
Solid Four -modern and reliableBest 4-Cyl -245 bhp, efficientDefinitive G02 -the one to buy
Best Diesel -improved over N47Torquey Six -refined and efficientHigh Power, High Cost -budget for maintenanceUltimate X4 -expensive to maintainEngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership VerdictSolid Four -modern and reliableBest 4-Cyl -245 bhp, efficientDefinitive G02 -the one to buyBest Diesel -improved over N47Torquey Six -refined and efficientHigh Power, High Cost -budget for maintenanceUltimate X4 -expensive to maintain
The G02 rule
A £4,500–£7,000 B58 recon against a £20,000–£35,000 M40i sits at 13–35% of the car's value -well within our 70% BMW scrap threshold. For an X4 M at £25,000+, a £6,000–£11,000 S58 recon is 24–44% -a repair decision, not a scrap question. These are high-value cars; the replacement cost is a manageable proportion of the vehicle's worth. But beware of S58 crank hub issues -budget for preventative work if buying used.
Key Takeaways
Which G02 Costs Least To Own?
B47D20B (xDrive20d) -proven diesel efficiency, low CO2, strong economy.
Which G02 Costs Most To Own?
S58B30A (X4 M Competition) -crank hub risk, expensive parts, high running costs.
Which G02 Is Best Value?
B58B30 (M40i) -the definitive G02 engine, modern reliability, strong performance, and often the sweet spot in the range.
B58
Oil Filter Housing Gasket Leak (M40i)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
Have the oil filter housing inspected at every service -a £400–£1,000 gasket replacement is cheaper than the £4,500+ replacement that follows a catastrophic oil loss. On a £25,000+ car, this is a manageable cost of ownership.
S58
Crank Hub Failure (X4 M / X4 M Competition)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
If you're buying an X4 M, budget for a crank hub fix if the car is modified or you plan to modify it -£1,800–£3,000 is cheaper than the £6,000+ replacement that follows a failure. On a stock car, it's a risk you can manage, but the peace of mind is worth the cost.
B47/B57
Diesel EGR Cooler & DPF (xDrive20d, xDrive25d, xDrive30d)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
If you're buying a diesel G02 for urban use, budget for DPF maintenance -£400–£1,200 for a clean or EGR cooler replacement is cheaper than the £3,000+ replacement that follows a catastrophic failure.
B48
Cooling System & PCV (xDrive20i, xDrive30i)
Affected models:
Typical failure mileage:
Root cause:
Our Recommendation
Have the cooling system and PCV valve inspected at every major service -a £300–£800 preventative repair is cheaper than the £2,500+ replacement that follows a failure.
VariantEngine Code
Used (Supply)
Reconditioned (Supply)
Rebuilt (Supply)
Labour HoursScope note: All variants listed are G02 only. The X4 M (F98) is technically a separate model designation but shares the G02 platform. The xDrive30d (B57 six-cylinder diesel) was available in European markets but not in North America.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Live FeedBMW X4 M40i G02
B58
Manchester
Oil leak from filter housing, burning smell3
enquiries
Updated MonthlyBMW X4 M Competition G02
S58
BirminghamCrank hub investigation, tuned car2
enquiries
Updated MonthlyBMW X4 xDrive20d G02
B47
LondonEGR cooler leak, coolant loss2
enquiries
Updated MonthlyMost Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Scope note: All variants listed are G02 only. The X4 M (F98) is technically a separate model designation but shares the G02 platform. The xDrive30d (B57 six-cylinder diesel) was available in European markets but not in North America.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,000–£7,000 (reconditioned, supply only)
[BMW-QUOTE]
Most Common Failures
Live FeedBMW X4 M40i G02
B58
ManchesterOil leak from filter housing, burning smell3
enquiries
BMW X4 M Competition G02
S58
BirminghamCrank hub investigation, tuned car2
enquiries
BMW X4 xDrive20d G02
B47
LondonEGR cooler leak, coolant loss2
enquiries
Updated MonthlyTrusted G02 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real G02 owners, as part of the Engine Finders network.
Compare G02 Engine Replacement Companies
see prices, warranty terms and supply & fit options side‑by‑side before you commit.
UK Engine Replacement Services for G02
covering every variant from xDrive20d to X4 M Competition, with supply‑only or full supply & fit available nationwide.
Find the best BMW X4 G02 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.
Compare BMW X4 G02 Engine Prices on EnginesMarket
