The Porsche MDB.XA is a 3,996 cc, V8 naturally aspirated petrol engine produced between 2020 and 2023. It features a 90-degree bank angle, direct fuel injection, dual overhead camshafts (DOHC), and a flat-plane crankshaft derived from motorsport development. In standard tune it delivers 419–441 kW (570–600 PS) with torque ranging from 470–480 Nm, optimized for high-revving responsiveness and track-focused dynamics.
Fitted exclusively to the 911 GT3 RS (992) and limited-run 911 GT3 R (road-legal homologation), the MDB.XA was engineered for uncompromising motorsport-derived performance with road legality. Emissions compliance was achieved via port-assisted direct injection, variable valve timing on intake and exhaust, and a gasoline particulate filter (GPF), ensuring adherence to Euro 6d standards from launch.
A documented concern involves premature wear of the hydraulic cam phaser solenoids under sustained high-RPM operation, potentially causing variable timing drift and misfires. This issue, highlighted in Porsche Service Information Bulletin 9835/2022, is linked to thermal stress on early solenoid coil windings. From 09/2022, Porsche implemented updated solenoids with improved thermal shielding.
All production years (2020–2023) meet Euro 6d standards (VCA UK Type Approval #VCA/EMS/9278).
The Porsche MDB.XA is a 3,996 cc V8 naturally aspirated petrol engineered for ultimate track performance with road compliance (2020–2023). It combines a motorsport-derived flat-plane crankshaft with port and direct injection to deliver explosive throttle response and linear power. Designed to meet Euro 6d from launch, it integrates a GPF without compromising high-RPM durability or acoustic purity.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,996 cc | |
| Fuel type | Petrol | |
| Configuration | V8, DOHC, 32-valve, 90° bank angle, flat-plane crank | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 102.0 mm × 60.8 mm | |
| Power output | 419–441 kW (570–600 PS) @ 8,500 rpm | |
| Torque | 470–480 Nm @ 6,300–7,000 rpm | |
| Fuel system | Combined port and direct injection (PFI+GDI) | |
| Emissions standard | Euro 6d | |
| Compression ratio | 13.7:1 | |
| Cooling system | Water-cooled with dual-circuit layout | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with hydraulic cam phasers | |
| Oil type | Porsche C3 (SAE 0W‑40) | |
| Dry weight | 214 kg |
The flat-plane crank enables an 8,500 rpm redline and race-derived throttle response but demands strict adherence to RON 98 fuel and Porsche C3 oil. Oil changes every 10,000 km or 12 months are critical, especially for circuit use. Pre-09/2022 engines should have cam phaser solenoids inspected per SIB 9835/2022. The GPF requires periodic high-RPM driving to prevent clogging, though carbon buildup is rare due to port injection cleaning intake valves.
Oil Specs: Requires Porsche C3 (0W‑40) specification (Porsche SIB 9150/2017). Equivalent to ACEA C3 and BMW LL‑04.
Emissions: Euro 6d certification applies to all MDB.XA models (2020–2023) (VCA Type Approval #VCA/EMS/9278). No market exceptions.
Power Ratings: Measured under ISO 1585. 441 kW output requires RON 98 fuel (Porsche TIS Doc. 992-ENG-505).
Porsche Technical Information System (TIS): Docs 992-ENG-501, 992-ENG-502, 992-ENG-505
Porsche Service Information Bulletin (SIB) 9835/2022, 9150/2017
VCA Type Approval Database (VCA/EMS/9278)
ISO 1585: Road vehicles – Engine test code
The Porsche MDB.XA was used exclusively in Porsche's 992 platform with rear-engine mounting and homologation-special applications. This engine powered the road-legal 911 GT3 RS and the limited 911 GT3 R homologation model, with differences in ECU mapping and exhaust resonance tuning. From 2022, updated cam phaser solenoids improved high-RPM reliability. All variants are documented in Porsche technical bulletins.
Locate the engine code stamped on the rear face of the right cylinder bank near the flywheel housing (Porsche TIS 992-ENG-510). The 7th VIN digit is ‘D’ for MDB.XA applications. Pre-2022 engines use cam phaser solenoid part number 9A5.110.901.00; post-2022 units use 9A5.110.901.01 with thermal shielding. Visual ID: lightweight magnesium valve covers with ‘GT3 RS’ laser etching; individual throttle bodies and titanium connecting rods (visible during teardown). ECU is Bosch MDG10 mounted near firewall—calibration distinguishes standard GT3 RS from homologation GT3 R.
The MDB.XA's primary reliability risk is hydraulic cam phaser solenoid degradation on pre-2022 builds, with elevated incidence in track-driven vehicles and sustained high-RPM usage. Porsche internal durability reports from 2023 indicated a notable rate of timing-related repairs before 25,000 km in competition-prepped builds, while UK DVSA records show minimal emissions-related failures due to robust GPF integration. Oil quality and operational discipline make adherence to OEM oil and fuel specifications critical.
Analysis derived from Porsche technical bulletins (2020–2023) and UK DVSA failure statistics (2021–2023). Repair procedures should follow manufacturer guidelines.
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