The diesel that responds best to a remap
The N47 is BMW’s 2.0-liter inline four-cylinder turbodiesel, built from 2007 to 2015 with common rail injection and a variable geometry turbo. It replaced the older M47 and powered a huge span of cars, from the 116d and 118d through the 320d and 520d to the X1 and X3. Diesels of this type make their power through torque and boost, which is exactly why BMW N47 tuning is so effective: a well-judged remap can lift both figures meaningfully while the engine still drives like a relaxed daily.
Why the gains are real, not marketing
A petrol engine of this size would barely notice a map change, but a turbodiesel is a different case. The N47 leaves the factory with conservative boost and fuelling set for emissions and noise targets, so there is genuine slack to recover. Depending on the exact version, stock outputs run from around 115 hp up to roughly 215 hp on the twin turbo variants, and a stage one remap commonly adds strong mid-range torque that makes overtaking and loaded driving far easier. Just as useful, the extra pull arrives low in the rev range, so you feel it in everyday driving rather than only when chasing the redline.
Factory outputs across the range
It helps to know where your car starts before planning changes. The engine appeared in many states of tune over its life, and the table below shows the broad spread rather than every single variant. Confirm your own figure from the build data, since emissions standards and model year both affect it.
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Version
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Typical output
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Example cars
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Entry
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around 115 hp, 260 Nm
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116d, 316d
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Mid
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around 143 hp, 320 Nm
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118d, 318d, 520d
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High
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around 184 hp, 380 Nm
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120d, 320d
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Twin turbo
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around 204 to 215 hp, 450 Nm
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123d, 125d
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Giving the tune room to work
A remap asks the engine to flow and burn more, so the supporting hardware has to keep pace. A less restrictive downpipe lowers exhaust back pressure and helps the variable geometry turbo spool, while a larger intercooler, like the E8x and E9x 120d and 320d kits stocked here, keeps intake temperatures in check so the map does not pull fuel on a hot run. Fitted together, these BMW N47 upgrades turn a safe paper tune into consistent, repeatable performance instead of a figure that fades once the engine heats up.
Match the downpipe to your emissions setup
Diesel exhaust parts are not one size fits all, so a quick check saves trouble before you order:
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Confirm the emissions standard, since EURO5 and EURO6 cars use different downpipe designs
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Note whether the car runs a DPF, a catalyst, or both, as that changes the correct part
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Check the chassis code, because 1, 3 and 5 Series fitments differ
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Keep local road rules in mind, as some exhaust changes are intended for track use
The one job to do before any power
No N47 plan should skip its headline weakness. Early engines, mainly those built between 2007 and 2011, are known for timing chain wear, with a telltale rattle from the gearbox end of the block, and because the chain sits at the rear, the repair is labour-heavy. Confirming a healthy or already replaced chain comes first, and with that settled, the engine responds to sensible changes with the easy, torque-rich pull that makes these diesels such effortless long-distance cars.
