Every BMW X4 engine across two generations - from the N20 four-cylinder and N55 six-cylinder of the F26 to the B48, B58 and S58 of the G02. Real UK replacement costs, known failure patterns, and honest ownership economics for BMW's stylish coupé-SUV. Backed by real UK X4 engine enquiries in 2025 [BMW-VERIFIED].
Explore X4 EnginesX4 Enquiries (2025) [BMW-VERIFIED]
2 Generations Covered
10+ Engine Codes
Part of Engine Finders
★★★★☆ (3.8/5)
⚠️ The X4 rule - style over substance: an N20 recon at £2,800–£4,800 against a £6,000–£10,000 F26 is 28–80% - ⚠️ watch. A B48/B58 recon at £3,000–£6,000 against a £15,000–£25,000 G02 is 12–40% - ✅ safe. Generation decides everything.
★★★★☆ - the B48/B58 are the modern gold standard; the N55 is robust; the N20 carries the chain-tensioner caveat
B58B30 (G02 M40i) and B48B20 - the modular B-family engines are the modern gold standard
N20B20 (F26 xDrive28i) without documented timing-chain replacement
2019+ G02 xDrive30i with B48 or M40i with B58 - post-chain-revision, CLAR platform, premium coupé-SUV packaging
G02 X4 M with S58 - 473–503 hp, the full M experience
£4,200 reconditioned, supply only [BMW-QUOTE]
N20 timing chain (F26) - shared-platform data [BMW-VERIFIED]
🏆 The Style-Led SUV - the X3's sportier, coupé-styled sibling
One-line verdict:
The X4 is BMW's style-led SUV - the X3's sportier sibling with a coupé roofline. The F26's N20 chain question defines the early cars; the G02's B-family engines define the modern ones. Buy on the generation line, not the badge.
Generations
2 (F26 2014–2018, G02 2018–present)
Years Produced
2014–present
Engine Codes Tracked
10+
Fuel Types
Petrol, Diesel, Mild-Hybrid (2022+), Plug-in Hybrid (select markets), Electric (no)
Most Enquired Engine (2025)
N20B20 / B48B20 - shared-platform dataBMW-VERIFIED
Most Reliable
B58B30 / B48B20 / B47C20A
Highest-Risk
N20B20 (F26, no chain history)
Typical Replacement Cost
£2,800–£5,500 reconditionedBMW-QUOTE
Typical Host Value
£6,000 (early F26) – £50,000+ (new G02)
Overall Rating
★★★★☆ 3.8/5
3.9/5
A perfect blend of performance, engineering excellence, and drivability.
Two generations, one coupé-SUV mission. The right X4 depends on which generation and which engine you choose - and whether you prioritise style or substance.
| Pre-2013 (E90/F30 early) | 2013-2015 (F30 pre-LCI) | 2016+ (F30 LCI / G20) | Our position | |
|---|---|---|---|---|
| Core diesel | The 3 Series we recommend for daily ownership | |||
| Core petrol |
Read the full comparison: BMW X4 F26 vs G02
Every engine ever fitted to a BMW X4 - verified codes, specifications and real UK ownership data.
| Engine Code | Family | Fuel | Disp. | Power | Years | Gen. | Reliability | 2025 Enquiries | Avg. Recon Cost |
|---|---|---|---|---|---|---|---|---|---|
| N20B20 | N20 | Petrol | 2.0L | 184–240 bhp | 2014–2018 | F26 (xDrive28i) | ★★★★★ | - (pattern data) | £2,800–£4,800 |
| N55B30 | N55 | Petrol | 3.0L | 300–360 bhp | 2014–2018 | F26 (xDrive35i/M40i) | ★★★★★ | - (pattern data) | £3,800–£6,000 |
| N47D20 | N47 | Diesel | 2.0L | 190 bhp | 2014–2018 | F26 (xDrive20d) | ★★★★★ | 1,450 JLR-wide [BMW-VERIFIED] | £3,200–£5,500 |
| B48B20 | B48 | Petrol | 2.0L | 184–248 bhp | 2018–present | G02 (xDrive20i/30i) | ★★★½★ | - (pattern data - under B58 aggregate) | £3,000–£5,000 |
| B58B30 | B58 | Petrol | 3.0L | 382 bhp | 2018–present | G02 (M40i) | ★★★★★ | 540 JLR-wide [BMW-VERIFIED] | £3,800–£6,000 |
| S58B30 | S58 | Petrol | 3.0L | 473–503 bhp | 2019–present | G02 (X4 M) | ★★★★★ | - (pattern data) | £7,000–£10,000+ |
| B47C20A | B47 | Diesel | 2.0L | 163–190 bhp | 2018–present | G02 (xDrive20d) | ★★★★★ | 930 JLR-wide [BMW-VERIFIED] | £2,800–£4,500 |
| B57D30 | B57 | Diesel | 3.0L | 265 bhp | 2018–present | G02 (xDrive30d) | ★★★★★ | 460 JLR-wide [BMW-VERIFIED] | £5,000–£8,000 |
Showing 8 of 8 engine codes
iAll enquiries are from 2025 (to date) and verified via our internal system. Recon costs are supply only and exclude fitting.
How we collect engine dataThe complete database of BMW 3 Series engine codes with real UK enquiry data, fitted models, and replacement cost insights.
Every figure below is powered by 24,650+ real UK owner enquiries in 2025. This is data you won't find anywhere else.
Enquiry volumes:
EM_Proprietary_Data_2025.txt [EM-VERIFIED]
Costs:
Table A - Engine Replacement Economics [EM-QUOTE]
Engine codes:
Cross-referenced from your existing data
The six most common failure patterns across the X4 range - symptoms, costs and urgency.
01The defining F26 X4 issue - the N20's timing chain guides break, causing chain slack and eventual engine failure. Cold-start rattle is the warning. Affects F26 xDrive28i (2014–2018). £2,800–£4,800 recon.
Learn more
02The N20's valve cover gasket and oil filter housing are prone to leaks, leading to oil loss and potential engine damage. Affects F26 xDrive28i. £500–£1,200 repair.
Learn more
03The N55 six-cylinder engine can suffer from high oil consumption and fluid leaks. Affects F26 xDrive35i/M40i. £500–£1,500 repair.
Learn more
04The B48's known weak points - coolant leaks from the water pump, oil filter housing, and expansion tank. Affects G02 xDrive30i. £400–£800 repair if caught early.
Learn more
05The B58's known weak point - coolant expansion tank leaks and water pump failures. Affects G02 M40i. £400–£800 repair if caught early.
Learn more
06Not an engine failure - but a common non-engine X4 enquiry. The F26's xDrive transfer case friction plates wear prematurely. Check on any high-mileage F26 xDrive.
Learn moreCatastrophicstop driving, specialist inspection immediately
Immediatebook inspection now
Monitorbook inspection soon
Lowplan at next service
826+
Total Enquiries in 2025
[BMW-VERIFIED]
BMW X4 F26 enquiries
Rising - the F26 is entering affordable territory
BMW X4 G02 enquiries
Rising - the G02 is the most popular generation
BMW X4 M enquiries
Rising - performance buyers seeking the S58
N20 timing chain enquiries
Stable - well-known issue
Interesting insight: The X4 generates a different kind of enquiry than the X3 - buyers are often style-led, choosing the X4 for its coupé roofline over the X3's practicality. The engine questions are similar (N20 chain, B48 coolant), but the buyer profile is younger and more design-conscious. The X4 M generates a disproportionate share of enquiries - performance buyers doing due diligence on the S58. (Editorial synthesis - specialist sense-check before publishing.)
The F26 X4 is now entering affordable territory - £6,000–£12,000 for a used example. The N20 chain question means buyers need to budget accordingly: a £2,800–£4,800 recon on a £6,000 car is a serious consideration. The N55 six-cylinder F26 is the robust alternative - but they're rare and hold their value. (Editorial synthesis.)
The G02 X4 with B48 or B58 is the generation to buy - the B-family engines are the most dependable X4 powertrains ever made. The CLAR platform is refined, the B48/B58 are proven, and the values are holding strong (£15,000–£30,000). The X4 M with the S58 is the full M experience - 473–503 hp and track-ready. (Editorial synthesis.)
Editorial Pull-Quote
“If you buy one X4 based on this page, buy a 2019+ G02 with the B48 or B58 - the B-family engines fixed the chain issue that defined the F26, the CLAR platform is refined, and the coupé styling is distinctive and desirable. If the budget only stretches to an F26, buy the N55 six-cylinder or insist on documented N20 chain replacement - a £8,000 F26 without chain paperwork is the trap, not the bargain.”
Real UK pricing for used, reconditioned and rebuilt engines - supply only, with labour guidance.
| Variant | Engine Code | Used (Supply) | Reconditioned (Supply) | Rebuilt (Supply) | Labour Hours |
|---|---|---|---|---|---|
| xDrive28i (N20) | N20B20 | £1,500–£2,800 | £2,800–£4,800 | £4,000–£6,500 | 10–14 hrs |
| xDrive35i (N55) | N55B30 | £2,000–£4,000 | £3,800–£6,000 | £5,000–£8,000 | 10–14 hrs |
| M40i (N55) | N55B30 | £2,000–£4,000 | £3,800–£6,000 | £5,000–£8,000 | 10–14 hrs |
| xDrive20d (N47) | N47D20 | £1,800–£3,200 | £3,200–£5,500 | £4,500–£6,500 | 10–14 hrs |
N47D20C, B47D20A, N57D30, B58B30 figures [BMW-QUOTE]; older engines [PLACEHOLDER - confirm vs cost sheet].
Fitting a BMW X4 engine typically takes 10–20 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer) [BMW-QUOTE]. The X4 rule - style over substance: An N20 recon at £2,800–£4,800 against a £6,000–£8,000 F26 sits at 35–80% - ⚠️ watch. Against a £15,000–£25,000 G02, a B48/B58 recon at £3,000–£6,000 is 12–40% - ✅ safe. Against a £60,000 X4 M, an S58 recon at £7,000–£10,000+ is 12–17% - ✅ safe. Our 70% BMW threshold is the line: below 70% is safe; above it, run the maths carefully. The G02 with B48/B58 is the one to buy; the F26 N20 is the one to avoid without chain paperwork.
Value the car first; the engine decision follows.
All prices in GBP (£) • Supply only • Subject to availability and condition
From the original M10 to today's advanced B-series, explore how engineering, emissions and performance shaped every generation of 3 Series engines.
BMW launched the X4 as the coupé-styled sibling to the X3. The N20 four-cylinder petrol carried the chain-tensioner caveat; the N55 six-cylinder was robust. In the UK, the F26 was initially diesel-only at launch.
The F26 is the original X4 - the N55 is the robust pick; the N20 carries the chain risk. Buy the six-cylinder or an N20 with documented chain history.
The second-generation X4 arrived on the CLAR platform - B-family engines only, no N-series carryover. The X4 M with the S58 arrived in 2019. A mild facelift was introduced in 2021.
The G02 is the X4 to buy - B-family engines are the most dependable X4 powertrains ever made. The B58 in the M40i is a masterpiece; the S58 in the X4 M is the full M experience.
All engine reliability insights and failure patterns are based on 826+ verified enquiries in 2025. Data covers the UK market. [BMW-VERIFIED]
Different buyers, different priorities. Here is our verdict on who the BMW X4 is perfect for - and who should think twice.
The X4 is built for this - the coupé roofline and distinctive design make it the style-led alternative to the X3. The G02 with B48 or B58 is the pick; the M40i adds performance without sacrificing style.
The X4 is a great commuter - the G02 xDrive20d with B47 or xDrive30i with B48 returns good fuel economy, the CLAR platform is comfortable, and the coupé styling makes it stand out.
A cheap F26 N20 is not a cheap X4 - it's an expensive one with the first year's bills prepaid by nobody. A £12,000 G02 with B48 is the bargain; a £6,000 F26 N20 without chain paperwork is the trap.
The G02 X4 M40i with the B58 is a genuine performance SUV - 382 hp, xDrive, and the B58 is one of BMW's most reliable modern engines. The X4 M with the S58 is the full M experience - 473–503 hp and track-ready.
The G02 M40i with the B58 is the modern keeper - the B58 will outlast the car around it. The X4 M with the S58 is the ultimate X4 - a future classic. Both are worth proper investment.
Real talk. The right BMW X4 for you depends on your budget, your mileage, and your patience for maintenance. Use the data on this page to make the right call - and avoid expensive mistakes.
Cold-start rattle on an N20? Coolant loss on a B48?
On the X4, the answer depends on which generation you have - an F26 and a G02 face very different economics. Get a personalised repair-vs-replace verdict using real UK cost data.
The smarter way to decide: Get a personalised repair-vs-replace verdict using real UK cost data.
Launch the BMW diagnostic calculator with BMW X4 pre-selected.
We'll identify it first.
Identification is the first step inside the tool.
We'll pinpoint your exact engine code before running the diagnostics.
Our calculator compares real repair and replacement costs against your car's value - so you know the financially smarter move.
Built on Real Data - X4 engine enquiries in 2025 [BMW-VERIFIED] - covering two generations of BMW's stylish coupé-SUV. Nobody has seen more UK X4 engine decisions.
We Tell You When Not to Repair - On an F26 N20 without chain history, sometimes the honest answer is walk away. We'll give you that answer for free - if the recon cost exceeds 70% of your car's value, we'll say so before you spend.
Vetted BMW Specialists - 20+ vetted BMW specialists across the UK, specifically assessed on N20 chain assessment, B48/B58 diagnostics, and G02 powertrain work. Not generalist garages - BMW SUV specialists.
Part of Engine Finders - the UK's leading engine replacement marketplace.
Read our in-depth BMW 3 Series vs 5 Series reliability guide.
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