The McLaren M838T R is a 3,799 cc, twin‑turbocharged V8 petrol engine produced between 2015 and 2021. Developed in collaboration with Ricardo, it features a flat‑plane crankshaft, dry‑sump lubrication, and dual overhead camshafts per bank. In standard form for the 675LT, it delivered 496 kW (675 PS), with torque figures of 700 Nm, enabling exceptional track — focused acceleration.
Fitted exclusively to the limited‑edition 675LT and 675LT Spider, the M838T R was engine…
Production years 2015–2021 meet Euro 6 standards for limited road use .
The McLaren M838T R is a 3,799 cc twin‑turbo V8 engineered for track-focused supercars (2015-2021). It combines a flat‑plane crankshaft with twin variable‑boost turbochargers to deliver explosive power delivery and high‑revving character. Designed to meet Euro 6 standards for limited road use, it prioritizes performance above all else.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,799 cc | |
Fuel type | Petrol | |
Configuration | V8, DOHC, 32-valve, flat-plane crank | |
Aspiration | Twin-turbocharged | |
Bore × stroke | 93.0 mm × 69.9 mm | |
Power output | 496 kW (675 PS) @ 7,100 rpm | |
Torque | 700 Nm @ 5,000–6,500 rpm | |
Fuel system | Direct injection (Bosch HDEV6) | |
Emissions standard | Euro 6 | |
Compression ratio | 8.7:1 | |
Cooling system | Water-cooled with auxiliary oil coolers | |
Turbocharger | Twin variable-boost units (Garrett) | |
Timing system | Chain-driven | |
Oil type | McLaren C30 Spec (SAE 0W-40) | |
Dry weight | 208 kg |
The McLaren M838T R was used exclusively in the McLaren 675LT platform with longitudinal, mid-mounted installation. This engine received specific adaptations-lighter internals, revised turbochargers, and optimized cooling-for the 675LT's track focus, creating interchange limits with the standard M838T. All adaptations are documented in OEM technical bulletins.
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The M838T R's primary reliability consideration is thermal stress on exhaust components under sustained track use. McLaren service data indicates a higher replacement rate for pre-catalytic converter oxygen sensors and turbocharger wastegate actuators in vehicles with significant track history. Aggressive driving and insufficient post-session cool-downs accelerate wear, making adherence to McLaren's specific track-day maintenance schedule critical.
Analysis derived from manufacturer technical service bulletins and industry workshop records. 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 M838T R is a robust, track-focused engine. Its long-term reliability is excellent for road use but depends heavily on maintenance, especially after track sessions. Key wear items like sensors and actuators may need earlier replacement in high-performance applications. Strict adherence to McLaren's service schedule is paramount.
The most documented issues are premature failure of pre-catalytic converter oxygen sensors, wear in the turbocharger wastegate actuators, and potential high-pressure fuel pump (HPFP) wear under extreme conditions. These are addressed in specific McLaren service bulletins for the 675LT.
The M838T R engine was used exclusively in the limited-production McLaren 675LT (2015-2016) and 675LT Spider (2016). It is a higher-output, track-optimized variant of the standard M838T found in the 650S and other models of that era.
Yes, but cautiously. The M838T R is already highly optimized. ECU remaps can yield modest gains, but significant power increases require upgraded turbos, fuel system, and engine internals. Such modifications void warranties and increase stress on an already highly-strung engine, demanding expert calibration.
Fuel economy is not a primary design goal. Expect approximately 15-18 L/100km (15-13 mpg UK) in combined driving. Consumption will be significantly higher during spirited or track driving. The official EU combined figure for the 675LT is 11.9 L/100km (24 mpg UK), but real-world figures are typically much higher.
Yes. Like virtually all modern high-performance engines, the M838T R is an interference design. A timing chain failure would almost certainly result in catastrophic valve and piston damage, requiring a complete engine rebuild.
McLaren mandates the use of its proprietary C30 specification oil, which is a 0W-40 synthetic. This specific formulation is critical for protecting the engine's bearings, turbos, and variable valve timing system under the extreme conditions the 675LT is designed for.
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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