Bootmod3 B58 Guide | BMW M140i, M240i, 340i, M340i & X3 M40i | Authorised UK Dealer

Bootmod3 B58 Guide | BMW M140i, M240i, 340i, M340i & X3 M40i | Authorised UK Dealer

Bootmod3 B58 Tune – Which B58 Do You Have and How Much Will It Gain?

Authorised UK Dealer · Instant digital activation · UK support · Updated October 2026

One engine, many cars

The B58 is BMW's 3.0-litre turbocharged six-cylinder, fitted to a wide range of models from 2016 on. BMW's own figures for some of the most popular ones:

Model	Factory power / torque	bootmod3 figures to use
M240i (F22/F23, 2016 on)	340 hp / 500 Nm	Other B58
X3 M40i (G01, 2018)	360 hp / 500 Nm	Other B58 (2020-on cars: B58-D)
M340i (G20, 2019 on)	374 hp / 500 Nm	B58-D (2020-on cars)

Also covered: M140i, 340i, 440i, 540i, 640i, 740i, 840i, Z4 M40i, X4 M40i and X5, X6 and X7 xDrive40i (full list below). Not sure which figures apply to your car? Send us your registration and we'll check.

How much more power? bootmod3's own figures

bootmod3 quotes fuel in US octane. US 91 octane is UK standard unleaded (95 RON); US 93 octane is UK super unleaded (98 RON).

B58-D engines (2020-on G20 M340i, X3 M40i, X4 M40i)

Map	Power / torque
Stage 1, UK standard unleaded	up to +18% / +28%
Stage 1, UK super unleaded	up to +21% / +30%
Stage 2, UK standard unleaded	up to +22% / +33%
Stage 2, UK super unleaded	up to +25% / +35%

Other B58 engines (cars without the BMW M Performance Power Kit)

Map	Power / torque
Stage 1, UK standard unleaded	up to +18% / +26%
Stage 1, UK super unleaded	up to +20% / +26%
Stage 2, UK super unleaded	up to +26% / +32%

Ethanol blends (E30, E50) and race fuel add more, and Stage 2+ maps exist for upgraded hardware; the full list is on the licence page.

What that means in practice (our rough arithmetic, not a dyno figure): a 374 hp M340i on Stage 1 with super unleaded works out at roughly 450 hp, and a 340 hp M240i at roughly 410 hp. Real results vary from car to car.

What bootmod3 actually does

bootmod3 is a cloud-based tuning app. You plug into your car's OBD port (under the dashboard), choose a ready-made "off-the-shelf" (OTS) map in the app, and flash it to the engine computer. The engine then uses more of its real capability: more power, a much stronger mid-range and sharper throttle.

• One OTS map is included with your licence, plus any maps marked "FREE".
• Switch maps, read and clear fault codes, and log live data from the app.
• You can go back to standard (stock) at any time.

Stage 1 or Stage 2?

Stage 1	Stage 2
No hardware changes needed The most common choice Ideal for daily driving	Needs supporting hardware, usually a high-flow downpipe More performance Pick the map that matches the fuel you use

The B58 is known for responding well to Stage 1 alone, so most owners start there.

Is my car covered?

bootmod3 lists these B58 BMWs:

• F20/F21 M140i (2016–2019)
• F22/F23 M240i (2016 on) and G42 M240i (2021 on)
• F30/F31/F34 340i (2016–2019) and G20 M340i (2019 on)
• F32/F33/F36 440i (2016 on)
• G01 X3 M40i (2017 on) and G02 X4 M40i (2018 on)
• G30/G31 540i and G32 640i (2017 on)
• G11/G12 740i (2016 on)
• G14/G15/G16 840i (2020 on)
• G29 Z4 M40i (2018 on)
• G05 X5 and G06 X6 (2019 on), G07 X7 xDrive40i (2018 on)

Toyota GR Supra (A90/A91) owners: the Supra has its own bootmod3 licence. See the Supra licence →

Newer cars: vehicles with November 2019 or newer engine software may need a one-off bench unlock before they can be flashed through the OBD port. Send us your registration or VIN before you buy and we'll check.

Gen 2 B58 and CustomROM

bootmod3's advanced CustomROM V2 features (switching between 4 maps from the steering wheel, flex fuel, launch control and more) are for Gen 2 B58 cars only. There is no simple model-year rule for which cars are Gen 2, so if CustomROM matters to you, send us your registration or VIN and we'll check before you buy.

What you need before you start

• A B58 BMW from the list above
• A way to connect to the car: an ENET cable (most reliable, recommended for the first flash) or the bootmod3 WiFi adapter
• A phone, tablet or laptop: iOS 13 or later, Android 5.0 or later, Windows 10 or later, or macOS 10.15 or later
• An internet connection
• Recommended: a battery charger connected while flashing, to prevent voltage drops

What happens after you order

1. You place your order.
2. We activate your licence, usually the same day and often within minutes during working hours.
3. You receive your access details from us.
4. You log in to bootmod3 and apply your activation.
5. You connect to your car and choose an off-the-shelf (OTS) map.
6. You flash your car.

How long does it take? First-time setup is about 10–15 minutes, the first flash a few minutes, and later map changes are quicker still. There is nothing to post and nothing to fit.

Is it safe?

bootmod3 works with the engine's built-in protections, such as knock control and temperature limits, which stay in place. As with any performance increase:

• Your engine should be healthy and well maintained before tuning.
• Keep up with servicing and use good-quality fuel, especially on Stage 2.
• You can go back to the standard map at any time.

Support: what to expect

We provide UK-based help with your licence, activation, cables, setup and flashing basics. For vehicle-specific tuning, logs or advanced diagnostics, support comes directly from the bootmod3 team, who manage the software and calibrations, so you get specialist answers from the source.

Why buy from VIMOTU

• Authorised UK bootmod3 dealer: genuine licences only, no grey-market keys
• Fast digital activation, same day during working hours
• UK-based support, no overseas delays
• Digital-first business: no storefront overheads, better pricing for you

Common questions

Is the M140i the same engine as the M340i?
Both use the 3.0-litre B58, but BMW updated the engine over the years. That is why bootmod3 publishes separate figures for the newer B58-D cars.

Do I need a downpipe?
Not for Stage 1. Stage 2 usually needs one.

Can I go back to stock?
Yes. You can revert to the standard map at any time.

Do I need a mechanic?
No. It's a do-it-yourself process from your phone or laptop.

How do I receive my licence?
Digitally, after purchase. Nothing is posted.