BMW B37, B47 and B57 Turbo Diesel Engines

B37 1.5 turbo diesel.
Chronology
The B37, B47 and B57 are part of BMW's new 2014 modular series of three, four and six cylinder engines with a common cylinder size of 500cc. The B37 is 1.5 litre, the B47 2.0 and the B57 3.0. The B37 and B47 can be mounted longitudinally for rear wheel drive cars or transversely for front wheel drive installations.
These engines were first sold in 2014 depending on model. The B37 powers the MINI One D, 116d, and 216d. The B47 is used on the 316d (detuned), MINI Cooper SD, 318d, 320d and all other four cylinder diesels.
The B57 is only used on the new 730d at present but will doubtless migrate to the X5, X6 and possibly higher powered 3 and 5 series models. At the time of writing most details are provisional for the B57.

B37 in a 218d Active Tourer front wheel drive.
Design
All three engines share the same basic features of four valves per cylinder, common rail injection and rear mounted timing chains. They have double VANOS camshaft timing and use the Valvetronic system in place of a conventional throttle body. The crankshafts and conrods are made from forged steel and there are balancer shafts to improve smoothness. The water pump is an "intelligent" on-demand electric type.
The B37 and B47 use single scroll Bosch-Mahle turbos but with variable geometry inlets to reduce lag. I suspect these are the new cast aluminium turbos as used on the B38 petrol engine.
The common rail fuel system runs at 2000 bar (29,400psi). The compression ratio is 16.5:1 for the B37 and B47.
The higher power B47 fitted to the X1 / X5 xDrive 25d uses multi-stage high and low pressure turbos and runs a revised fuel system at 2500bar.
Like the petrol version these engines have numerous acoustic panels, but they also serve to thermally insulate the engine. Not only does this help the engine warm up faster but it retains it's heat too. BMW claim the engine could be as much as 10C warmer the morning after it's been used.
These engines are EU6 compliant, depnding on model and gearbox choice fuel consumption is 0.1 to 0.4 litres/km less than with the N47 generation despite better power and torque delivery throughout the rev range. This is partly accomplished by means of a new pressure sensor inside the cylinder which ensures the most efficient mode of operation
All version are made at BMW's Steyr plant in Austria, it can produce up to 5500 per day. There are rumours of a quad turbo B57, time will tell.

B47 in a 2015 520d.
Variants
Code | Size | Power bhp@rpm |
Torque lb/ft@rpm |
BHP/ litre |
Torque/ litre |
Made | Bore x Stroke |
Timing | Weight (kg) |
VANOS | Used in |
B37 | 1.5 | 93 @ 4000 113 @ 4000 |
162 @ 1750-2250 200 @ 1750-2250 |
101 103 |
147 153 |
2015 on | 84x90 | Chain | ? | Dual + Valvetronic |
214d, MINI One D 116d, 216d |
B47 | 2.0 | 114 @ 4000 147 @ 4000 167 @ 4000 186 @ 4000 220 @ 4400 227 @ 4400 227 @ 4400 |
199 @ 1250-2750 243 @ 1750-2750 265 @ 1500-2750 294 @ 1750-2500 330 @ 1500-3000 330 @ 1500-3000 377 @ 1500-3000 |
57 73 83 93 110 113 113 |
99 121 132 147 165 165 188 |
2015 on | 84x90 | Chain | ? | Dual + Valvetronic |
316d 218d, 318d, 418d MINI Cooper SD 120d, 220d, 320d 125d, 225d X1 25d X5 25d |
B57 | 3.0 | 260 @ 4000 | 441 @ 1500-3000 | 87 | 147 | 2015 on | 84x90 | Chain | ? | Dual + Valvetronic |
730d |

B37 in front wheel drive configuration with intercooler.
Problems
If you're thinking of buying a diesel BMW check out the petrol vs diesel page first.
Because these warm up faster than most diesels thanks to the thermal panels and other features they may be less prone to soot creation, a major problem in previous models.
In my opinion the oil service interval is too long, that's true of most modern BMW engines. I'd change the oil a bit sooner than recommended. It's VITAL to use the correct grade with these engines as it's long life oil, using the cheap stuff with such long service intervals is a very false economy.
In most countries you'll have a Diesel Particle Filter (DPF). These store diesel soot and burn it off at high temperatures. Which is a problem if the car does lots of short journeys and never gets warm. If it clogs up it's an MoT failure and the car will drive poorly. Removing it may be illegal and a new one can be very expensive. All modern diesels have these, not just BMWs.
Many of these engines will get chipped by their owners to boost performance. Generally this isn't a bad thing and can have excellent results. But beware of cars where things have been taken a bit too far or done with "magic" ebay devices.