BMW F30 vs G20: Which 3 Series Saloon Should You Buy?
F30 vs G20 is the current 3 Series buying decision. F30 (2012 to 2019) is the value play: deepest used pool, well-understood failure patterns, prices at the floor on older builds. G20 (2019 onwards) is the modern play: B-series engines throughout, ULEZ-compliant from launch, iDrive 8 from 2022 LCI, 48V mild-hybrid from 2020. The real question is whether the £6,000 to £10,000 G20 premium is worth it for your use case.
Quick verdict
G20 if budget allows and you want the newer tech and ULEZ certainty. F30 if value is the priority and you can verify the build is post-LCI (mid-2015) with the B-series engines. Pre-LCI F30 (2012 to 2015) carries timing-chain risk on N47 / N20 and lacks ULEZ compliance on diesels. G20 is uniformly ULEZ-compliant but carries the 48V mild-hybrid as an emerging long-tail concern from 2020 onwards.
Side-by-side comparison
| Dimension | F30 | G20 | Notes |
|---|---|---|---|
| Years on UK market | 2012 to 2019 | 2019 to present | F30 ended as G20 started; clean transition. |
| ULEZ compliance | Diesel: post-LCI only. Petrol: all builds | All engines, all years | G20 is uniformly ULEZ-compliant. |
| Modal diesel engine | N47 (pre-2015), B47 (post-2015) | B47 (with 48V mild-hybrid from 2020) | G20 inherited B47 from late F30. |
| Modal petrol engine | N20 (pre-2015), B48 (post-2015) | B48 (with 48V mild-hybrid from 2020) | Same engines; G20 adds mild-hybrid hardware. |
| iDrive generation | iDrive 5 / 6 (pre-LCI), iDrive 7 (some late F30) | iDrive 7 (pre-LCI), iDrive 8 curved display (post-2022) | G20 LCI is meaningfully better infotainment. |
| Apple CarPlay | LCI 2015 onwards | Yes, all builds | Pre-LCI F30 cannot retrofit CarPlay. |
| Mild-hybrid 48V | Not fitted | From 2020 builds onwards | G20 BSG and 48V battery are emerging wear items. |
| Typical 320d price (60k mi) | £9,500 to £13,000 (post-LCI) | £20,000 to £25,000 | G20 commands ~£10k premium for newer car. |
| Used pool depth | Deepest UK 3 Series pool | Emerging from PCP returns | F30 has 5x the listings on AutoTrader at any time. |
| Insurance group | 20 to 28 typical | 23 to 30 typical | G20 slightly higher due to newer tech. |
F30: deeper look
F30 (2012 to 2019) is the modal modern used 3 Series. Pre-LCI (mid-2012 to mid-2015) carries N47 timing-chain risk on 320d and N20 timing-chain risk on 320i / 328i; post-LCI (mid-2015 to 2019) uses B47 diesel and B48 petrol, both ULEZ-compliant. F30 chassis wear items are well-known: electric water pump, FRM3 module on early cars, rear lower control arm bushes past 80,000 miles. Used prices are at the floor on pre-LCI cars (£3,500 to £6,000 for high-mileage 320d SE) and ramp up for post-LCI Shadow Edition (£16,000 to £19,000).
G20: deeper look
G20 (2019 onwards) is the current 3 Series. All engines are B-series modular family from launch. ULEZ is uniformly compliant. iDrive 7 on pre-LCI (2019 to mid-2022), iDrive 8 with curved-glass display on LCI (mid-2022 onwards). Mild-hybrid 48V was rolled out across most engines from 2020 onwards, adding a BSG (Belt-driven Starter Generator) and small 48V battery, both of which have emerging wear patterns. Most G20s in UK classifieds in 2026 are still under BMW warranty or BMW Approved Used scheme.
Decision logic
Budget threshold: under £15,000 buys you a clean post-LCI F30 320d M Sport with 60,000 miles, full history, ULEZ-compliant. £20,000 to £25,000 buys you a 2020 to 2021 G20 320d Pre-LCI at the same mileage. The £6,000 to £10,000 G20 premium gets you a newer chassis with newer tech, warranty status (most G20s are still under coverage), and depreciation profile in your favour for the next 3 to 5 years. F30 buyers get a more mature used market with well-understood failure patterns and lower service rates.
UK 2026 pricing comparison
| Scenario | F30 | G20 | Notes |
|---|---|---|---|
| Pre-LCI 320d M Sport, 100k mi | £6,000 to £9,000 (F30 N47) | Not available (G20 starts 2019) | F30 N47 cars are firmly in long-tail value territory. |
| Post-LCI 320d M Sport, 60k mi | £12,000 to £15,000 (F30 B47) | £20,000 to £25,000 (G20 B47) | Comparable cars, G20 around £8-£10k more. |
| M Sport Shadow Edition 320d, 30k mi | £16,000 to £19,000 (F30) | Not directly equivalent on G20 | F30 Shadow Edition is late-cycle special. |
| Post-LCI M340i (B58 inline-six) | £18,000 to £23,000 (F30 340i) | £30,000 to £38,000 (G20 M340i) | Mid-range performance comparison. |
| M3 (separate chassis, S55 / S58) | £22,000 to £85,000 (F80 M3) | £50,000 to £130,000 (G80 M3) | M3 is a separate chassis comparison; see F80 vs G80. |
Recommendation by scenario
| Scenario | Pick | Why |
|---|---|---|
| Sub-£10,000 budget | Pre-LCI F30 320d (B47 post-Sept 2014) | Cheapest entry into modern 3 Series ownership. Avoid N47 if budget allows the LCI B47 premium. |
| £12,000 to £15,000 budget | Post-LCI F30 M Sport (320d B47 or 330i B48) | Sweet spot for value modern 3 Series. ULEZ-compliant, B-series engines. |
| £20,000 to £25,000 budget | Early G20 320d M Sport (2020 to 2021) | G20 with iDrive 7 and BMW warranty / BMW Approved status. Skip mild-hybrid concerns by going pre-2020 (rare) or accept the 48V long-tail. |
| £26,000+ budget | LCI G20 (2022 onwards) | Best tech package; iDrive 8 with curved display; latest software. |
| London commuter, ULEZ-first | Either, but verify build date on F30 diesel | G20 is uniformly ULEZ-compliant. F30 320d needs post-Sept-2014 build to be compliant. |
| Long-distance motorway | F30 / G20 330d xDrive (B57) | Inline-six diesel is the long-distance pick on both generations. Choose generation on budget. |
Bimmer.AI is designed to help you identify BMW-specific buyer risks before you travel, negotiate, or pay for an inspection. It does not replace a physical inspection by a qualified mechanic, a legal vehicle-history check (e.g. HPI Check), or independent verification of finance, stolen, or write-off status. Repair-cost ranges are indicative UK figures that vary by region, specialist, parts supply, and labour rates.
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Run a Bimmer.AI buyer report →Frequently asked questions
Is the G20 a better car than the F30?
Newer, yes; better in every sense, depends on your priorities. G20 wins on infotainment (iDrive 8), ULEZ certainty, current safety tech, and warranty status. F30 wins on value, deepest used pool, well-understood failure patterns, and mature parts supply. For a tight budget, F30 is the cleaner buy. For full-spec long-term ownership, G20 is the better proposition.
How much more expensive is the G20 vs F30?
Around £6,000 to £10,000 premium for comparable age and mileage. A 2018 F30 320d M Sport at 60,000 miles is £12,000 to £15,000; a 2020 G20 320d M Sport at 60,000 miles is £20,000 to £25,000. The premium reflects newer chassis, newer engines (mild-hybrid), newer iDrive, and warranty status (most G20s are still under cover).
Should I avoid the mild-hybrid G20?
Not categorically. The 48V Belt-driven Starter Generator (BSG) is a wear item that BMW has issued software and hardware campaigns on, but it's covered under warranty for most cars in 2026. Replacement out of warranty is £800 to £1,800. For G20 cars within their 3-year manufacturer warranty or BMW Approved Used scheme, this isn't a buyer concern.
Does the G20 have the same engines as the F30?
Mostly yes. G20 uses B47 (320d), B48 (320i, 330i), B57 (330d, M340d), B58 (M340i). F30 used the same engines from LCI (mid-2015) onwards. Pre-LCI F30 used the previous-generation N47, N20, N55 (which carry their own failure patterns). The cleanest comparison is F30 LCI vs G20: same engines, different chassis tech.
Is the G20 worth the iDrive 8 upgrade?
If you use iDrive heavily (navigation, Apple CarPlay, climate, Drive Recorder), yes. iDrive 8 (LCI 2022 onwards) is meaningfully more responsive than iDrive 7 (pre-LCI G20) or iDrive 6 (F30 LCI). If you mainly use Apple CarPlay or Android Auto and treat iDrive as a host, the difference is smaller. £4,000 to £5,000 premium for LCI G20 over pre-LCI is the upgrade cost.
Can I retrofit Apple CarPlay to a pre-LCI F30?
No. Pre-LCI F30 (mid-2012 to mid-2015) uses iDrive 5 / 6 which cannot retrofit Apple CarPlay. Post-LCI F30 (mid-2015 onwards) uses iDrive 6 NBT with CarPlay activated by BMW dealer or indie coding (£100 to £250). G20 has CarPlay standard from launch.
What's the F30 LCI vs F30 pre-LCI?
Same chassis, different engines and infotainment. Pre-LCI (2012 to mid-2015) uses N47 diesel and N20 petrol with iDrive 5 / 6. LCI (mid-2015 onwards) uses B47 diesel and B48 petrol with iDrive 6 NBT and LED headlight option. LCI is the cleaner used buy by some margin: B-series engines plus ULEZ on diesel.
Will the G20 hold value better than the F30?
Most likely yes for the next 3 to 5 years, then convergence. G20 is newer in the depreciation cycle; F30 is mature and trading near the floor on pre-LCI cars. Buying for resale: G20 LCI (2022+) has the strongest residual. Buying for use: F30 LCI is the value compromise.