BMW B57D30 engine code explained
B57D30 is the full code for BMW's current modular 3.0-litre straight-six diesel, launched in the G11 730d in 2015 and fitted to the 330d, 530d, 540d, 730d, 740d, X3 30d and M40d, X5 30d and 40d, X6 and X7 from 2017. It came in single-turbo (30d), twin-turbo (40d, M40d, 540d) and, for three years only, quad-turbo form (M550d, M50d, 750d). The 48V mild-hybrid versions arrived in 2020. It is the strongest and cleanest diesel BMW has sold.
Quick answer
The B57D30 is the 3.0-litre straight-six diesel of the BMW B57 family, built 2015-present. Bimmer.AI scores the family 8 / 10: one of the safest used BMW engines to buy. The tables below give every output tier and sticker letter BMW used on this stem and which cars got them; the failure table is the same one that powers the B57 family guide.
How to read B57D30
| Part of the code | Meaning |
|---|---|
| B | B-series modular engine generation (2013 onwards) |
| 57 | engine family number within the B-series |
| D | diesel, longitudinal (rear-drive platform) |
| 30 | displacement in tenths of a litre: 3.0 litres |
| K / U / M / O / T / S + digit | output tier and revision, appended in BMW's internal naming (for example B57D30O1) |
| A / B / C / D | parts-catalogue engine version printed on the engine cover sticker (for example B57D30A) |
B57D30 output tiers and which cars have them
| Code | Output | Cars | Notes |
|---|---|---|---|
| B57D30O0 | 265 bhp, single turbo | 330d (G20 2019-2020), 530d (G30 2017-2020), 630d GT, 730d (G11 2015-2019), X3 xDrive30d (G01 2017-2020), X4 30d, X5 xDrive30d (G05 2018-2020), X6 30d, X7 30d | The volume tier |
| B57D30O1 | 286 bhp, single turbo, 48V mild hybrid | 330d LCI, 530d LCI (G30 2020-2023), 730d LCI, X3 / X4 30d LCI (2021 on), X5 / X6 / X7 30d (2020 on), 630d GT LCI | MHEV from 2020; check the starter-generator on used cars |
| B57D30T0 | 320 to 326 bhp twin-turbo (2017-2020), 340 bhp with 48V mild hybrid (2020 on) | 540d xDrive (G30 / G31 2017-2023), 740d (G11), 840d (G14 / G15 / G16), X3 M40d and X4 M40d (2018 on), X5 xDrive40d (G05 2020 on), X6 40d, X7 40d | Two-stage turbo. NOT the quad-turbo |
| B57D30S0 | 400 bhp, quad-turbo (B57S) | M550d xDrive (G30 / G31 2017-2020), 750d / 750Ld xDrive (G11 / G12 2017-2020), X5 M50d (G05 2019-2020), X6 M50d (G06 2020), X7 M50d (G07 2019-2020) | Dropped in 2020 when BMW ended the quad-turbo diesel |
B57D30 sticker letters: B57D30A, B57D30B, B57D30C
As with the N57, the parts letters follow the turbo count: A single, B twin, C quad. The badge is the reliable guide: 30d single, 40d / M40d / 540d twin, M50d / M550d / 750d quad. Listings that call a 540d or an X3 M40d a quad-turbo are wrong; those cars have two turbos and are far closer to a 530d in complexity than to an M550d.
| Sticker code | What it denotes |
|---|---|
| B57D30A | Original single-turbo B57 (2015 to 2020) in the parts catalogue. |
| B57D30B | Twin-turbo applications (540d, 740d, 40d, M40d). |
| B57D30C | Quad-turbo B57S (M550d, M50d, 750d). |
Known problems on every B57D30
Failure data is held once, per engine family, so this table is identical to the BMW B57 guide. Cost ranges are indicative UK figures.
| Failure mode | Severity | Frequency | Typical onset | UK repair range |
|---|---|---|---|---|
| AdBlue / SCR system fault | Moderate | Very common | 30 to 100k mi | £300 to £1,500 |
| Quad-turbo system complexity (B57S: M50d / M550d / 750d only) | Serious | Uncommon | 80 to 150k mi | £600 to £3,000 |
| DPF regen failure | Moderate | Common | 50 to 120k mi | £400 to £1,500 |
| Timing chain tensioner / guide wear (high mileage) | Mild | Uncommon | 120 to 200k mi | £1,800 to £3,000 |
| Injector failure (high mileage) | Mild | Uncommon | 100 to 180k mi | £400 to £700 |
Long-term verdict
Currently BMW's strongest, cleanest diesel and arguably the best diesel BMW has ever sold. The 530d delivers 265bhp / 620Nm with 45+ mpg real-world. The twin-turbo 540d (320bhp, 680Nm; 340bhp mild hybrid from 2020) is a genuinely fast diesel, and the short-lived quad-turbo B57S (M50d, M550d, 750d; 400bhp, dropped in 2020) is the most insane production diesel BMW has ever produced. Very few known issues, AdBlue system glitches are the most common complaint. Long-term data past 150,000 miles is still emerging but early signs are excellent. Fully ULEZ compliant. If budget allows, prefer this over any earlier BMW diesel.
Check a specific B57D30 listing
Paste any BMW B57 listing, VIN or registration. Bimmer.AI identifies the exact engine and returns the buyer report in 30 seconds.
Run a Bimmer.AI buyer report →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.
Frequently asked questions
Is the 540d a quad-turbo B57D30S0?
No. The 540d xDrive uses the twin-turbo B57D30T0: 320 bhp on 2017 to 2020 cars and 340 bhp with a 48V mild hybrid from the 2020 LCI, and it ran to the end of G30 production in 2023. The quad-turbo B57D30S0 (400 bhp) went only into the M550d xDrive, the X5 / X6 / X7 M50d and the 750d, all between 2017 and 2020, after which BMW dropped it. Same applies to the X3 M40d and X5 40d: twin-turbo, not quad.
B57D30 problems: what should I check?
The B57 has no systemic mechanical weakness yet. The buyer checks are the AdBlue / SCR system (NOx sensors from around 60,000 miles, £300 to £500 each; pump and heater faults; a countdown-to-no-start warning is a walk-away until resolved), DPF regeneration history on short-journey cars, the plastic oil-filter-housing gasket, and on 2020-onwards cars stored faults on the 48V starter-generator. On the quad-turbo B57S, add turbo actuators and a specialist inspection.
Which B57D30 should I buy?
The 530d or X5 30d single-turbo (O0, or O1 mild hybrid from 2020) for almost everyone: 45 mpg, ULEZ-compliant, the simplest six-cylinder diesel BMW makes. The twin-turbo 540d / 40d / M40d if you tow or want pace, at little extra risk. The quad-turbo M550d / M50d only with full history and a budget for four turbos' worth of plumbing.
Which BMWs have the B57D30 engine?
The B57D30 went into the following cars, by output tier. B57D30O0 (265 bhp, single turbo): 330d (G20 2019-2020), 530d (G30 2017-2020), 630d GT, 730d (G11 2015-2019), X3 xDrive30d (G01 2017-2020), X4 30d, X5 xDrive30d (G05 2018-2020), X6 30d, X7 30d; B57D30O1 (286 bhp, single turbo, 48V mild hybrid): 330d LCI, 530d LCI (G30 2020-2023), 730d LCI, X3 / X4 30d LCI (2021 on), X5 / X6 / X7 30d (2020 on), 630d GT LCI; B57D30T0 (320 to 326 bhp twin-turbo (2017-2020), 340 bhp with 48V mild hybrid (2020 on)): 540d xDrive (G30 / G31 2017-2023), 740d (G11), 840d (G14 / G15 / G16), X3 M40d and X4 M40d (2018 on), X5 xDrive40d (G05 2020 on), X6 40d, X7 40d; B57D30S0 (400 bhp, quad-turbo (B57S)): M550d xDrive (G30 / G31 2017-2020), 750d / 750Ld xDrive (G11 / G12 2017-2020), X5 M50d (G05 2019-2020), X6 M50d (G06 2020), X7 M50d (G07 2019-2020). The two-letter family badge is B57; any listing that quotes the family code is talking about one of these.
Is the BMW B57D30 reliable?
Bimmer.AI scores the B57 family 8 out of 10, which makes the B57D30 one of the safest used BMW engines to buy. Currently BMW's strongest, cleanest diesel and arguably the best diesel BMW has ever sold. The 530d delivers 265bhp / 620Nm with 45+ mpg real-world. The twin-turbo 540d (320bhp, 680Nm; 340bhp mild hybrid from 2020) is a genuinely fast diesel, and the short-lived quad-turbo B57S (M50d, M550d, 750d; 400bhp, dropped in 2020) is the most insane production diesel BMW has ever produced. Very few known issues, AdBlue system glitches are the most common complaint. Long-term data past 150,000 miles is still emerging but early signs are excellent. Fully ULEZ compliant. If budget allows, prefer this over any earlier BMW diesel.
What does B57D30 mean?
B is the B-series modular engine generation (2013 onwards), 57 is the family number, D means diesel, longitudinal (rear-drive platform), and 30 is the displacement in tenths of a litre (3.0 litres). BMW appends an output tier and revision (K, U, M, O, T or S plus a digit) in its own naming, and the parts catalogue adds a version letter (A, B, C) that is what you see on the engine cover.