B47 and B57 overview
From roughly 2014 onward, most modern BMW diesels you meet will be a B47 (2.0-litre four-cylinder) or a B57 (3.0-litre six). Both can be brilliant when maintained with care — smooth, efficient, and well suited to long motorway days.
We see more workshops turning to these units as older N47/N57 cars reach the point where repair bills start to feel emotional. If that sounds familiar, you are not alone.
Key differences
- B47: lovely in 318d/320d/420d and many X3 20d models — compact and economical
- B57: a beautiful fit for heavier 5 Series, 6 Series, and X5/X6 applications where torque is king
- Both need respectful attention to AdBlue/SCR and DPF on Euro 6 cars — your workshop knows the drill
Buying advice
Please specify the exact suffix (B47D20A, B57D30B, and so on) and talk to your installer about software and immobiliser pairing before you buy. A ten-minute conversation upfront can save a fortnight of frustration later — we are genuinely happy to help with that chat.