The McLaren M840T is a 3,994 cc, twin — turbocharged V8 petrol engine produced between 2017 and 2023. Developed in collaboration with Ricardo, it features a flat — plane crankshaft, dry — sump lubrication, and dual overhead camshafts per bank. This powerplant delivers outputs ranging from 530 kW (710 PS) to 588 kW (789 PS), with torque figures between 770–800 Nm, enabling exceptional throttle response.
Fitted exclusively to McLaren's Sports and Super Series models — incl…
Production years 2017–2023 meet Euro 6d-TEMP standards for applicable markets (VCA UK Type Approval #VCA/MCL/840T).
The McLaren M840T is a 3,994 cc twin-turbocharged V8 engineered for high-performance supercars (2017-2023). It combines a flat-plane crankshaft with dry-sump lubrication to deliver explosive acceleration and high-RPM stability. Designed to meet Euro 6d-TEMP standards, it prioritizes maximum power output within regulatory frameworks.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,994 cc | |
Fuel type | Petrol | |
Configuration | 90° V8, DOHC, 32-valve, flat-plane crank | |
Aspiration | Twin-turbocharged | |
Bore × stroke | 86.0 mm × 85.8 mm | |
Power output | 530–588 kW (710–789 PS) | |
Torque | 770–800 Nm @ 5,500–7,000 rpm | |
Fuel system | Gasoline direct injection (Bosch HDEV6) | |
Emissions standard | Euro 6d-TEMP | |
Compression ratio | 9.4:1 | |
Cooling system | Water-cooled with auxiliary oil coolers | |
Turbocharger | Twin mono-scroll turbochargers (Garrett) | |
Timing system | Chain-driven, dual-stage variable valve timing | |
Oil type | McLaren C30 Spec (SAE 0W-40) | |
Dry weight | 183 kg |
The McLaren M840T was used exclusively across McLaren's Super Series and Sports Series platforms with longitudinal, mid-mounted installation. This engine received minor ECU and cooling adaptations between the 720S and GT for power and thermal management, creating subtle calibration differences. All adaptations are documented in OEM technical bulletins.
The M840T's primary reliability focus is managing thermal stress under extreme conditions, with elevated incidence in track use or hot climates. McLaren service data indicates that adherence to maintenance schedules is paramount, while extended high-RPM operation without adequate cooldown can accelerate wear. Ambient temperatures and driving style make cooling system integrity and correct oil specification critical.
Analysis derived from McLaren technical bulletins (2017-2023) and UK DVSA failure statistics (2018-2023). Repair procedures should follow manufacturer guidelines.
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The M840T is a robust, high-performance engine when maintained meticulously per McLaren's schedule. Its primary vulnerabilities are linked to thermal stress and component wear under extreme use. Using the correct C30-spec oil and 98 RON fuel, along with avoiding extended high-RPM operation without cooldown, is crucial for long-term reliability.
Documented issues include high-pressure fuel pump failures, turbocharger wastegate rattle, oil cooler line leaks, and intake manifold runner valve faults. These are addressed in McLaren service bulletins. The engine is generally reliable for road use with proper care.
The M840T engine powered the McLaren 720S (2017-2023), GT (2019-2023), 600LT (2018-2019), and 765LT (2020-2021). It was the core powerplant for McLaren's Sports and Super Series during this period, replacing the earlier M838T engine.
Yes, the M840T responds well to ECU remapping, with reputable tuners offering safe gains of 50-100+ PS. Its robust internals, including forged pistons and connecting rods, can handle increased torque. However, significant power increases may require upgraded cooling, fueling, and drivetrain components to ensure reliability.
Fuel economy is not its forte. Expect combined figures around 20-25 mpg (UK) or 11.3-9.4 L/100km under normal driving. Aggressive driving or track use will drastically reduce this, potentially to single-digit mpg. The official WLTP combined figure for the 720S is 23.9 mpg (UK).
Yes. Like virtually all modern high-performance engines, the M840T is an interference design. A timing chain failure would result in catastrophic valve and piston damage. Fortunately, the chain-driven system is very robust and not a common failure point with proper maintenance.
McLaren mandates a very specific 0W-40 synthetic oil meeting their proprietary 'C30' specification. Using any other oil, even if it meets general industry standards, can void the warranty and potentially cause damage to the engine's sensitive components, particularly the turbos and dry-sump system.
Comprehensive technical documentation and regulatory references
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GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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