The McLaren M840T is a 3,994 cc, 90° V8 twin-turbocharged petrol engine produced between 2017 and 2023. Developed in partnership with Ricardo, it features dual overhead camshafts (DOHC), dry-sump lubrication, and a flat-plane crankshaft. This architecture delivers exceptional throttle response and a high specific output, with power ranging from 530 kW (710 PS) to 588 kW (789 PS) and torque figures between 770–800 Nm.
Fitted exclusively to McLaren’s Sports and Super Series models, including the 720S, GT, and 765LT, the M840T was engineered for extreme performance and driver engagement. Emissions compliance for road use was achieved through gasoline direct injection (GDI) and catalytic converters, meeting Euro 6 standards across its production run.
One documented engineering focus was managing heat soak in the twin-turbo system during sustained high-load operation. This was addressed in service updates, including revised turbocharger coolant routing detailed in McLaren Technical Service Bulletin TSB-M840T-01. The engine received incremental ECU and boost control refinements throughout its lifecycle to optimize performance and reliability.
All production years (2017–2023) meet Euro 6 standards for the markets in which the vehicles were sold (UK VCA Type Approval #VCA/MCL/720S).
The McLaren M840T is a 3,994 cc 90° V8 twin-turbocharged petrol engine engineered for high-performance supercars (2017-2023). It combines a flat-plane crankshaft with dry-sump lubrication to deliver explosive acceleration and high-revving character. Designed to meet Euro 6 standards, it balances track-focused performance with road-legal emissions compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,994 cc | |
| Fuel type | Petrol | |
| Configuration | 90° V8, DOHC, 32-valve | |
| Aspiration | Twin-turbocharged | |
| Bore × stroke | 88.3 mm × 81.0 mm | |
| Power output | 530–588 kW (710–789 PS) | |
| Torque | 770–800 Nm @ 5,500–7,000 rpm | |
| Fuel system | Gasoline direct injection (GDI) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 9.4:1 | |
| Cooling system | Liquid-cooled with auxiliary coolers | |
| Turbocharger | Twin mono-scroll turbochargers (Garrett) | |
| Timing system | Chain-driven | |
| Oil type | McLaren C30 Spec (SAE 0W-40) | |
| Dry weight | 183 kg |
The flat-plane crank provides a high-revving, race-derived character but demands meticulous maintenance using McLaren C30 0W-40 oil to protect bearings and turbos. Extended high-RPM operation requires monitoring oil temperature; the dry-sump system is robust but sensitive to incorrect fluid levels. Fuel must meet 98 RON (EU) or 93 AKI (US) minimum to prevent knock under boost. Pre-2020 models benefit from the TSB-M840T-01 coolant routing update to mitigate heat soak. Regular ECU health checks are advised to maintain optimal boost control.
Oil Specs: Requires McLaren C30 specification (0W-40) (McLaren Owner's Handbook). Not interchangeable with standard ACEA specs.
Emissions: Euro 6 certification applies to all model years (2017-2023) for designated markets (UK VCA Type Approval #VCA/MCL/720S).
Power Ratings: Measured under SAE J1349 standards. Peak output requires 98 RON fuel (McLaren Technical Service Bulletin TSB-M840T-01).
McLaren Technical Information System: Docs M840T-SPEC-01, TSB-M840T-01
VCA Type Approval Database (VCA/MCL/720S)
SAE International: J1349 Engine Power Certification Standards
The McLaren M840T was used exclusively across McLaren's Super Series and Sports Series platforms with longitudinal, rear-mid mounting and is not licensed to other manufacturers. This engine received model-specific ECU calibrations—higher boost for the 765LT and revised torque curves for the GT—creating software interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code 'M840T' cast into the front face of the engine block, near the alternator (McLaren TIS M840T-ID-01). The 8th VIN digit is 'M' for all M840T-equipped vehicles. Visually, it features a carbon fiber intake plenum and twin turbochargers mounted within the 'hot vee'. Critical differentiation from M838T: M840T has a 4.0L displacement (vs 3.8L) and revised cylinder heads. ECU part numbers are model-specific; software from a 720S is incompatible with a GT without reprogramming (McLaren TIS SW-COMPAT-01).
The M840T's primary documented focus is managing heat in the turbocharger system, with elevated thermal stress noted during track use. McLaren service data indicates the TSB-M840T-01 coolant update significantly reduced related incidents, while owner reports highlight the criticality of using correct oil specification. Sustained high-load operation without adequate cooling intervals can accelerate wear, making adherence to fluid specs and service intervals critical.
Analysis derived from McLaren technical bulletins (2017-2023) and aggregated owner service reports (2018-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MCLAREN M840T.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with MCLAREN or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
MCLAREN Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialMCLAREN documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
