McLaren Engine Codes Database

A McLaren engine code (e.g., M838T, M840T) identifies the engine family and displacement. M838T = 3.8L twin-turbo V8 (used in MP4-12C, 570S, P1). M840T = 4.0L twin-turbo V8 (used in 720S, Senna, GT). The code determines specifications, compatible parts, and performance characteristics. Source: McLaren Automotive Technical Documentation.

McLaren engines (M838T, M840T) are generally reliable with proper maintenance. Common issues include timing cover oil leaks (high replacement cost), thermostat failures on 570S models, and occasional electrical gremlins. The M840T in 720S shows good reliability. Regular servicing with correct oil specification is critical. Source: McLaren owner reports, Autocar reliability data.

The M840T (4.0L V8 in 720S, 750S) is considered the most reliable McLaren engine, benefiting from lessons learned with the M838T. The M838T is also robust but has more reported issues like timing cover leaks. Both engines are hand-built by Ricardo to high standards. Avoid early MP4-12C models (2011-2012) which had teething problems.

McLaren engines (M838T, M840T) use timing chains, not belts. The chains are designed for the life of the engine under normal conditions. However, the timing cover on M838T engines is prone to oil leaks, which is a costly repair. Regular oil changes with correct specification are essential to prevent chain wear.

With proper maintenance, McLaren M838T and M840T engines can exceed 100,000 miles. Key factors: use correct oil specification (McLaren-approved synthetic), regular servicing every 12,500 miles or annually, and address oil leaks promptly. The M840T shows better long-term reliability than early M838T variants. Source: McLaren Service Schedule.

McLaren engines are manufactured by Ricardo at their facility in Shoreham, UK. The M838T and M840T V8 engines are hand-assembled to McLaren's specifications. McLaren and Ricardo announced a renewed multi-year partnership in 2023 for future hybrid V8 powertrains. Source: Ricardo-McLaren Partnership Announcement, May 2023.

M838T: 3.8L (3,799cc) twin-turbo V8, 592-755 HP, used in MP4-12C, 570S, 650S, P1. M840T: 4.0L (3,994cc) twin-turbo V8, 710-789 HP, used in 720S, 750S, Senna, GT. The M840T has longer stroke, enhanced twin-scroll turbos, and improved thermal efficiency. Both use flat-plane crankshafts and direct injection.

No, McLaren does not and has never produced diesel engines. All McLaren road cars use petrol engines (M838T, M840T) or hybrid powertrains (P1, Speedtail, Artura). McLaren focuses exclusively on high-performance petrol and electrified powertrains.

Common 570S (M838T) issues include: timing cover oil leaks (expensive repair), blocked thermostats, aluminium panel corrosion, cracked door hinges, leaking front shocks, seat motor failures, and occasional electrical gremlins. Spark plug and fuel injector issues can cause misfires. Regular inspection and maintenance are essential. Source: McLaren owner forums, Autocar.

Common 720S (M840T) issues include: air brake system accumulator problems, electrical gremlins, door strut failures, and occasional software glitches. The M840T engine is generally more reliable than the M838T. Panel corrosion can occur. Most issues are minor and covered under warranty for newer vehicles. Source: McLaren owner reports.

McLaren engine replacement costs vary: M838T complete replacement £40,000-£60,000, M840T £50,000-£70,000. Timing cover oil leak repair on M838T: £8,000-£12,000 (labour-intensive). These are approximate costs; actual prices depend on model, year, and extent of damage. Extended warranty recommended for out-of-warranty vehicles.

McLaren specifies proprietary synthetic oil meeting McLaren standards (check owner's manual for exact specification). For M838T and M840T engines, use only McLaren-approved oil. Service intervals: 12,500 miles or annually (whichever comes first). Using incorrect oil can void warranty and cause engine damage. Source: McLaren Service Schedule.

The P1's M838TE hybrid powertrain is generally reliable but extremely complex and expensive to maintain. The 3.8L V8 (727 HP) + 176 HP electric motor system requires specialised McLaren technicians. Hybrid battery degradation can occur after 10+ years. Only 375 units were built (2013-2015), making parts rare and costly.

The engine code (M838T or M840T) is stamped on the engine block, typically visible on the timing cover or engine casing in the engine bay. On mid-engine McLarens, you may need to remove engine covers. The code is also listed on the V5C registration document under 'Engine Number'. Source: McLaren Service Documentation.

McLaren engines comply with Euro 5 (early M838T models) and Euro 6 (M840T and later M838T variants). All current McLaren models meet Euro 6d emissions standards. The hybrid Artura meets the latest Euro 6 emissions requirements. Check your V5C or VIN decoder for specific model compliance. Source: EU Regulation (EC) No 715/2007.