BMW 420d with the 20d engine on the DC Remapping 4WD dyno

BMW 20d · N47 & B47 diesel

BMW 320d & F Series 20d Stage 1 Remap

A Stage 1 map written for your car on our own 4WD dyno in Warrington. Any 184–190bhp 20d, from a 120d to a G30 520d, comes out at around 230bhp and 500Nm.

230bhpfrom 184–190bhp

500Nmfrom 380–400Nm

£449Stage 1

Book Your Tune Find Your 20d

★★★★★ 4.9 from 269+ Google reviews
xDrive-safe 4WD dyno
Same day, about 2 hours
Tuning BMWs for 15+ years

Which 20d have you got?

Two engines, one result

Before 2015 the 20d is the N47; from 2015 it is the B47. All of them land at around 230bhp and 500Nm on Stage 1, with no hardware and every factory emissions system left in place, so the car stays fully MOT compliant. Pick your car to book with it already filled in, or read the full N47 and B47 pages.

N47 2010 – 2015

F-series 20d, 163 / 184bhp

Standard163–184bhp · 380Nm

Our Stage 1230bhp 500Nm

Stage 1 custom dyno tune£449
+ xHP gearbox (auto)£325

Not locked. Straight on the dyno.

We have tuned over 500 N47s at Stage 1 and 2.

Everything about the N47 →

Book yours

120d 220d 320d 420d 520d X3 20d

B47 2015 – 2019

F-series LCI 20d, 190bhp

Standard190bhp · 400Nm

Our Stage 1230bhp 500Nm

Stage 1 custom dyno tune£449
+ xHP gearbox (auto)£325

Not locked. Straight on the dyno.

Same headline figures as the N47, with every factory system left in place.

Everything about the B47 →

Book yours

120d 320d 420d 520d X3 20d X4 20d

B47 2019 on

G-series 20d, 190bhp

Standard190bhp · 400Nm

Our Stage 1230bhp 500Nm

Stage 1 custom dyno tune£449
+ xHP gearbox (auto)£385

Built from June 2020: locked ECU, unlocked on our bench the same day, +£100. Built from June 2026: a newer lock we can’t open yet.

G20/G21 320d, G22 420d, G30/G31 520d, G01 X3, G42 220d and F40 120d.

Everything about the B47 →

Book yours

320d 420d 520d X3 20d 220d 120d xDrive

Not sure which you have? Check your exact car or check whether your ECU is locked.

Prices

What it costs

Fixed prices. The gearbox software is for automatic cars with the ZF8.

Stage 1

Stage 1 Custom Dyno Tune

Around two hours. No hardware needed.

Health check and fault scan before anything is touched
Map written live on our xDrive-safe 4WD dyno
Before and after dyno printout
Fully reversible, back to factory software at any time

£449

Book Stage 1

Stage 1 + xHP Most popular

Stage 1 + xHP Gearbox

£709 on G-series Save £125

Everything in Stage 1
Quicker, firmer ZF8 shifts with less hesitation
Torque limits raised to match the new map
Engine and gearbox done in the same visit

£649F-series

Book Engine + Gearbox

Built from June 2020? Add £100 for the same-day ECU unlock. Finance available · More on our BMW gearbox remap (xHP)

Measured on our dyno

BMW 20d results from our own dyno

We have been tuning BMW’s 2.0 diesel for over 15 years, from the N47 through to today’s B47. Every car below is a customer car, run on our in-house 4WD dyno in Warrington before and after the map. These are the printed figures.

BMW 420d Coupé

F32 · B47 2.0 diesel · Stage 1 + xHP ST3

Power: ~~178.6~~226.6+48.0
Torque: ~~399~~494+95

Read the build On our results page

BMW 420d Convertible

F33 · 2.0 diesel · Stage 1 + xHP ST3

Power: ~~180.2~~230.3+50.1
Torque: ~~390~~496+106

Read the build On our results page

The 20d in numbers

Engine: N47 (to 2015) and B47 (2015 on) 2.0 four-cylinder turbo diesel
Found in: 120d, 220d, 320d, 420d, 520d, X3 20d
Standard: 163–190bhp · 380–400Nm
Our Stage 1: 230bhp · 500Nm (369 lb-ft) on a healthy car
Gearbox: 6-speed manual or ZF 8HP auto · xHP (auto) £325 F-series, £385 G-series
ECU: N47: Bosch EDC17 · B47: Bosch MD1CS001
Locked ECU?: Cars built from around June 2020 have a locked ECU. We unlock it on our own bench, same day, for £100 on top of your tune. Cars built from June 2026 use a newer lock that can’t be opened yet. Check your reg
Stage 1 price: £449, custom mapped on our dyno

What 20d owners say on Google

4.9 from 269+ Google reviews

★★★★★

I had my BMW E82 120d sorted here yesterday. After a terrible flash map I needed a custom tune. I am unbelievably happy with the results. Dan took his time to take my car back to a stock ECU map and then performed his tune. The difference is night and day, nearly 500nm and 219bhp. Customer service is fantastic, great waiting room, highly recommended!!

Richard Houghton · BMW 120d E82 · Google review

★★★★★

Had my 2011 bmw 320d remapped today to Stage 2, Daniel who mapped it got it to 240bhp and 505nm torque. I've had this car 9 years and my only regret is I left it this long before having it done. Completely different car now. Thanks to Daniel for making me smile 😃 10/10

ryan williams · BMW 320d, 2011 · Google review

★★★★★

Brought my 118d msport here last weekend after seeing amazing reviews. Very pleased with my experience, car feels better than ever and feels so smooth. Very helpful with talking through each step and had a nice place to chill while car was being done. Even managed to get me booked in on the same day I had started to enquire about my remap. Overall an amazing experience that I would definitely recommend and will be coming back with many more cars

Wil Edward's · BMW 118d M Sport · Google review

Quoted word for word from our Google reviews. Read them all on Google.

How your day works

In for a couple of hours, driven home tuned

Every 20d goes on our V-Tech 4WD linked dyno. BMW’s xDrive can’t be run safely on a standard rolling road, and places that unplug the transfer box or switch the 4WD off in software often show badly over-read torque figures. Ours is mechanically linked, so xDrive cars run as they were built.

Health check

Fault scan and data logs first. DPF regeneration and minor adaptations are done before tuning where needed, at no extra cost.

Baseline run

Your car’s real standard figures, measured on the dyno, not taken from a brochure.

Map written live

Boost, fuelling and timing adjusted run by run against what your engine is actually doing.

Printout and keys

Before and after graph in your hand.

BMW 320d dyno chart, stock against DC Stage 1 custom — BMW 320d · stock vs our Stage 1

G-series 20d built from June 2020? No problem.

BMW and Alpina cars built from June 2020 have an encrypted ECU. We unlock it on our own bench the same day, rather than posting it away, and tune the car on the same visit. It adds £100 and no extra time. Cars built from June 2026 use a newer lock that can’t be opened yet: email sales@dcremappinguk.com with your reg and we’ll tell you when that changes.

Check Your Reg

FAQs

BMW 20d Tuning Questions

How much power will a Stage 1 remap add to my BMW 20d?

Our Stage 1 maps are custom-built on our in-house 4WD dyno and tailored to your exact BMW 20d, never a generic off-the-shelf file. You'll see a substantial, fully dyno-proven gain in both power and torque; the headline figures for this platform are shown at the top of this page. Because every map is refined over multiple runs, the results are realistic, repeatable and safe.

Is remapping my BMW 20d safe and reliable?

Yes. We tune strictly within the safe mechanical limits of your BMW 20d's engine and gearbox, monitoring temperatures, pressures and torque loads across multiple dyno pulls. We've spent 15+ years tuning these platforms, so our maps prioritise long-term reliability alongside performance.

Will a remap affect my warranty or insurance?

A remap is an aftermarket modification, so it's the owner's responsibility to declare it to their insurer. Our maps are fully reversible, we can return the BMW 20d to its factory software whenever you need, for example before a main-dealer visit.

Is the remap reversible?

Completely. It is fully reversible: your BMW 20d can be put back to its factory software at any time.

Will tuning improve my BMW 20d's fuel economy?

We tune for performance, not fuel economy, so we don’t promise or guarantee any MPG saving. How much fuel the car uses comes down mostly to how it’s driven, and using the extra performance will use more.

How long does it take, and do you tune on a dyno?

Most Stage 1 tunes are completed within a few hours; allow up to a day for combined ECU and gearbox work. Every BMW 20d is mapped on our in-house 4WD dyno in Warrington, never on the road, so the result is measured and consistent. You're welcome to relax in our customer waiting area while we work.

Can you tune a G-Series 20d built from June 2020?

Yes. BMW and Alpina cars built from June 2020 have an encrypted ECU, and we unlock it on our own bench during the same visit, so a G20 320d, G30 520d, G01 X3 20d or F40 120d is tuned the same day. The unlock adds £100 to your tune. Cars built from June 2026 use a newer lock that cannot be opened yet, so we cannot tune those for now.

Check Your Vehicle

See What Your Car Will Make

Pick your make, model and engine for the expected Stage 1 and Stage 2 gains, your price, and book straight from the result.

Make Model Generation Engine

Choose your make to begin.

Strapped down on our V-Tech 4WD linked dyno

Ready to book your 20d?

Book online in a couple of minutes: put your reg in and pick a date. Rather talk it through? Call us.

Book Your Tune Call 01925 819002

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