McLaren 720S Common Service Intervals & Maintenance Guide
The McLaren 720S follows a condition-based maintenance philosophy, but there are fixed intervals for critical fluids and inspections. Understanding these helps owners plan ahead and avoid costly unscheduled downtime.
Engine Oil (M840T)
The M840T twin-turbocharged V8 uses a dry-sump lubrication system. McLaren specifies Mobil 1 5W-40 or equivalent fully synthetic oil meeting ACEA A3/B4. The service interval is 12 months or 10,000 miles, whichever comes first. The oil filter is a cartridge-style unit located on the passenger side of the engine. Capacity including filter change is approximately 8.5 liters. The oil tank is separate from the engine block — common in track-focused cars — and is mounted in the rear of the passenger cell. Always check level via the instrument cluster, not a conventional dipstick.
Gearbox & Differential Fluid
The 720S uses a 7-speed dual-clutch transmission (SSG). Gearbox fluid change is specified at 3 years or 30,000 miles. Use only McLaren-approved Castrol Transmax ATF fluid. The rear differential, integrated into the gearbox casing, shares this fluid. Overfilling or using incorrect fluid will cause erratic SSG behavior and potential bearing damage.
Hydraulic Suspension System
The RaceActive Chassis Control II (RCC II) uses a dedicated hydraulic circuit with a reservoir, pump, and accumulators. The system operates at very high pressure — always depressurize before disconnecting any hydraulic lines. McLaren specifies Pentosin CHF 11S hydraulic fluid. A hydraulic fluid flush is required every 4 years or when the fluid appears dark/discolored. The four corner accumulators are wear items; a common symptom of accumulator failure is reduced ride quality and body roll.
Brake Fluid
DOT 4 brake fluid is used in the 720S. For track use, DOT 5.1 is recommended for higher boiling point. Annual replacement is advised for track-driven cars; every 2 years for road use. The electro-hydraulic brake booster is sensitive to moisture-contaminated fluid — spongy pedal feel is often the first symptom.
Spark Plugs
NGK SILZKGR8B8E iridium-tipped spark plugs are factory-fitted. Replacement interval is every 30,000 miles. Access requires removal of the rear deck panels and engine cover. The M840T uses a flat-plane crank layout with 8 cylinders; all 8 plugs are accessible from above with the engine cover removed.
Understanding the McLaren 720S Electrical Architecture
The 720S uses a high-speed CAN bus network with multiple domain controllers. Key ECUs include the Powertrain Control Module (PCM), the Vehicle Control Unit (VCU), the Active Brake Control (ABC) module, and the Body Control Module (BCM). Fault diagnosis requires a McLaren-compatible diagnostic tool — the MDS (McLaren Diagnostic System) — which communicates over both CAN and UDS (Unified Diagnostic Services) protocols.
Common electrical fault areas include:
- Low Li-ion 12V battery: The 720S uses a lithium-ion 12V ancillary battery (not lead-acid). It is located in the luggage bay. Capacity is approximately 40Ah. Trickle charging is essential for vehicles stored more than 3–4 weeks. Incorrect charging voltage will permanently damage the battery.
- PDU (Power Distribution Unit) fuses: Located behind the passenger seat. Fuse identification requires referencing the wiring diagram — most circuits are protected by smart fuses within the BCM rather than traditional blade fuses.
- EPB (Electronic Parking Brake) service mode: Before disconnecting the battery or working on the rear brakes, the EPB calipers must be placed in service mode via MDS. Failure to do so will prevent caliper piston retraction and can damage the actuator motors.
720S Body Structure & Panel Repair Notes
The McLaren 720S Monocage II is a one-piece carbon fiber safety cell that is not repairable in the conventional sense. Any damage to the tub requires specialized McLaren assessment. However, the outer skin panels — roof, doors, hood, decklid, and front/rear clamshells — are all removable and replaceable without structural repair.
Door gap adjustment is achieved via hinge eccentric bolts. Panel alignment tolerances are tighter than typical steel-body vehicles — 2mm maximum gap variation is the factory specification. Clamshell alignment (front and rear) is a multi-point adjustment process outlined in full in the body repair section of the SIS.
Frequently Used Torque Specifications
The following torque values are frequently referenced during routine 720S service. Always verify against the specific procedure in the SIS for your build date and specification:
- Wheel lug nuts (center-lock): 450 Nm (use McLaren single-nut torque socket)
- Engine sump drain plug: 40 Nm
- Suspension wishbone pivot bolts (front upper): 85 Nm
- Brake caliper mounting bolts (front): 195 Nm
- Gearbox drain/fill plugs: 35 Nm
- Driveshaft to hub flange bolts: 90 Nm + 90° turn
- Cylinder head bolts: multi-stage (see procedure DA-RM-01B001 in SIS)
How to Use This Service Manual
The Service Information System is organized by vehicle system. Navigate using the left-hand tree menu. Each procedure is assigned a unique document ID in the format DA-RM-[system code]-[subsystem]-[procedure number]. For example, DA-RM-05F003-04-002 refers to a powertrain (05) engine oil system (F003) procedure. Cross-references within procedures link to related documents and prerequisite steps automatically.
Use the search function (keyboard shortcut: Ctrl+K) to find procedures by component name, part number, or procedure type (e.g., "torque", "bleed", "remove/install"). The search index covers all 5,885 procedures and is updated in real time as you type.