The McLaren M840T is a 3,994 cc, twin — turbocharged V8 petrol engine co — developed with Ricardo and produced from 2017 to 2023. It features a flat — plane crankshaft, dual overhead camshafts (DOHC), and dry — sump lubrication, delivering outputs ranging from 585 PS to 720 PS. The flat — plane crank enables a high — revving, race — derived character with a distinctive exhaust note.
Fitted to the 720S, GT, and 600LT models, the M840T was engineered for explosive acceleration and…
Production years 2017–2023 meet Euro 6d-TEMP standards for all applicable markets .
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 extreme power and a high-revving character. Designed to meet Euro 6d-TEMP, it prioritizes track capability alongside road legality.
| 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 × 86.0 mm | |
Power output | 585–720 PS (430–530 kW) | |
Torque | 600–770 Nm @ 5,500–6,500 rpm | |
Fuel system | Gasoline direct injection (GDI) | |
Emissions standard | Euro 6d-TEMP | |
Compression ratio | 9.4:1 | |
Cooling system | Dual-circuit water-cooled | |
Turbocharger | Twin mono-scroll turbochargers (Garrett) | |
Timing system | Chain-driven | |
Oil type | McLaren C30 Spec (SAE 0W-40) | |
Dry weight | 183 kg |
The McLaren M840T was used across McLaren's Super Series platform with longitudinal, rear-mid mounting and no external licensing. This engine received model-specific power calibrations-720S (720 PS), GT (620 PS), 600LT (600 PS)-but no major hardware revisions affecting core compatibility. All adaptations are documented in OEM technical bulletins.
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The M840T's primary reliability focus is managing heat from its twin-turbo system, with elevated thermal stress noted during sustained track use. McLaren internal durability testing showed robust mechanical longevity under normal conditions, while service data indicates carbon buildup on intake valves as the most frequent maintenance item. Aggressive driving without proper cooldown cycles can accelerate turbo wear, making adherence to service protocols critical.
Analysis derived from McLaren technical bulletins (2017-2023) and aggregated dealer service reports (2018-2024). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M840T is a robust, race-derived engine with strong long-term reliability when maintained correctly. Its primary needs are strict adherence to service intervals, use of McLaren C30 0W-40 oil, and 98 RON fuel. The main long-term concern is intake valve carbon buildup, which is a maintenance item, not a design flaw.
The most frequent issues are intake valve carbon buildup requiring cleaning, potential turbo heat-related wear from track use without cooldown, and occasional high-pressure fuel pump failures. Coolant leaks from the thermostat housing are also a known, easily fixed concern.
The M840T powered the core Super Series models: the 720S (2017-2023), the GT grand tourer (2019-2023), and the track-focused 600LT (2018-2020). Power outputs varied by model but the core engine architecture remained consistent.
Aftermarket ECU tuning is common on the M840T-E platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
Fuel economy is not its forte. Expect around 15-18 L/100km (15-18 mpg UK) in mixed driving for a 720S. The GT might achieve slightly better figures (~14 L/100km) due to its gearing, while the 600LT will be thirstier. Track use will drastically increase consumption.
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 system is very robust and not a common failure point.
It requires McLaren's specific C30 specification oil, typically a 0W-40 synthetic. This is non-negotiable for protecting the turbos, dry-sump system, and engine internals. Using the wrong oil can void warranty and cause premature wear. Change intervals are 10,000 km or annually.
Comprehensive technical documentation and regulatory references
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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.
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