M-Engineering M-Tuner Calibration Suite for McLaren 720S 2018-2023

M-Tuner is M-Engineering's calibration suite for McLaren's 4.0-liter M840T twin-turbo V8, the engine behind the 720S, 765LT, Senna and GT. After a one-time ECU unlock, you own a tuning platform that lives on your laptop: flash Stage 1 or Stage 2 maps at home, switch between fuels on the fly, read and clear faults, and log data on every drive.

Live Map Switching comes at no extra charge. By default the off-the-shelf Stage 1 and Stage 2 calibrations load four slots: 91 octane, 93 octane, 100+ octane and a Valet map that limits boost, load and throttle. If you want a different slot layout, ask for it when you order. Original purchasers also get free updates between M-Engineering's off-the-shelf stages (Stage 1, Stage 2 and Stage 2+), so the software grows with the car as you add parts.

Key specs

Features

• Live Map Switching between the loaded slots
• Datalogging and live data
• Clear faults
• Dyno mode enable and disable
• Auto Start/Stop disable
• Left-foot braking
• Kickdown disable
• Loud start

Optional Motorsport Tuning Package (choose it in the selector above): Rolling anti-lag, custom closed-loop boost control, injector characterization, staged injection and fan override: custom code turns the cooling fans on at set points or on chosen map slots.

What is included

• M-Tuner v3 dongle for wireless OBD flashing
• M-Engineering maps built for the M840T
• On-the-fly Live Map Switching at no extra charge
• M-Engineering support
• Motorsport Tuning Package, only when selected

Required and recommended parts

• Stage 1 runs on stock downpipes, fuel system and turbos.
• Stage 2 requires aftermarket downpipes of 3 in or larger.
• Stage 2+ adds Injector Dynamics ID1050X injectors, and Stage 3 adds PT1200 turbochargers. Both are sold as complete M-Engineering power packages.
• M-Engineering recommends new factory spark plugs gapped to .022 and sticky tires run at lower pressures.

Frequently asked questions

Is this a bench flash or an OBD flash?
It starts on the bench and then moves to OBD. The M840T ECU is removed once and mailed to M-Engineering HQ for a one-time unlock. Once it is back in the car, you load maps, switch stages and update calibrations yourself through the OBD-II port with the wireless M-Tuner v3 dongle and a Windows 10 or 11 PC.

How much power does M-Tuner add?
M-Engineering documents its M840T results with wheel-horsepower dyno charts from a DynoJet 424 Linx, published in its calibration notes, rather than a single headline number. Output depends on the stage, the fuel slot and the supporting hardware on your car.

What does the Motorsport Tuning Package add?
It unlocks race-oriented code on top of the suite: rolling anti-lag, custom closed-loop boost control, injector characterization, staged injection and a fan override. It is not a standalone product, so it is offered here as an option on the suite.

Is there a warranty?
M-Engineering does not accept responsibility for voided factory warranties, and all sales are final. Plan your tune with that in mind.

Fitment notes

This suite covers the M840T-engined 720S, 765LT, Senna and GT. The Motorsport Tuning Package is an optional add-on and needs the suite to work.