The Porsche M 48.70 is a 3,596 cc, water-cooled flat‑six petrol engine produced between 2004 and 2005. It features dual overhead camshafts (DOHC), VarioCam Plus variable valve timing, and Bosch Motronic ME 7.8 electronic fuel injection. In standard form it delivered 257 kW (350 PS) and 385 Nm of torque, offering high-revving performance with strong top-end power for the 911 GT3 RS.
Fitted exclusively to the limited-production 996-generation 911 GT3 RS, the M 48.70 was engineered for track-focused performance with lightweight internals, increased compression, and optimized airflow. Emissions compliance was achieved via a sport-tuned three-way catalytic converter and precise lambda control, allowing Euro 3 compliance while maintaining race-derived character.
One documented concern is increased valve train wear under sustained high-RPM use, noted in Porsche Technical Service Bulletin TSB‑996‑04‑11. The aggressive cam profiles and high spring pressures accelerate tappet and guide wear if oil changes are extended beyond recommended intervals. From 2005, Porsche restricted M 48.70 production to homologation units, with successor engines receiving revised cam metallurgy.
All production years (2004–2005) meet Euro 3 standards (VCA UK Type Approval #VCA/EMS/4870).
The Porsche M 48.70 is a 3,596 cc flat‑six DOHC petrol engine engineered for the 996 GT3 RS (2004–2005). It combines VarioCam Plus with lightweight forged internals to deliver high-revving, track-capable performance. Designed to meet Euro 3 while prioritizing power density, it represents the pinnacle of the 996 GT3 engine lineage.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,596 cc | |
| Fuel type | Petrol | |
| Configuration | Flat‑6, DOHC, 24‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 100.0 mm × 76.4 mm | |
| Power output | 257 kW (350 PS) @ 7,200 rpm | |
| Torque | 385 Nm @ 5,500 rpm | |
| Fuel system | Bosch Motronic ME 7.8 electronic injection | |
| Emissions standard | Euro 3 | |
| Compression ratio | 11.6:1 | |
| Cooling system | Water-cooled with enlarged oil cooler and dual radiators | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with VarioCam Plus | |
| Oil type | Porsche C30 10W‑60 full synthetic | |
| Dry weight | 172 kg |
The M 48.70 delivers exhilarating high-RPM power but demands disciplined maintenance due to its race-derived valvetrain. Oil changes every 7,500 km with Porsche C30 10W‑60 full synthetic oil are essential to protect aggressive cam lobes and tappets. Use of 98 RON minimum (100 RON recommended) fuel prevents knock under high load. Extended track use requires cooldown periods and post-session oil analysis. Valve clearance inspections every 30,000 km are advised per TSB‑996‑04‑11 due to accelerated wear from high spring pressures.
Oil Specs: Requires Porsche C30 10W‑60 full synthetic oil (Porsche SIB TSB‑996‑04‑11). Lower-viscosity oils risk cam lobe scuffing.
Emissions: Euro 3 certification applies to all model years (2004–2005) per VCA Type Approval #VCA/EMS/4870.
Power Ratings: Measured under DIN 70020 standards. Power output assumes 100 RON fuel and optimal ignition timing (Porsche TIS Doc. 996‑PERF‑28).
Porsche Technical Information System (TIS): Docs 996‑GT3‑22, 996‑FUEL‑25, TSB‑996‑04‑11
VCA Type Approval Database (VCA/EMS/4870)
DIN 70020 Engine Power Certification Standard
The Porsche M 48.70 was used exclusively in Porsche's limited-run 996 GT3 RS with rear-engine, longitudinal mounting and no external licensing. This engine received platform-specific adaptations—lightweight crankshaft, titanium connecting rods, and track-calibrated oil pan—and from 2005 was phased out in favor of the M97/71 for the 997 generation, creating absolute interchange limits. All adaptations are documented in OEM technical bulletins.
The engine type is stamped on the left rear crankcase near the flywheel housing (Porsche TIS 996‑ID‑12). The 10th VIN digit indicates model year; 996 GT3 RS VINs begin with WP0ZZZ99 and include “GT3RS” in the model field. All M 48.70 engines feature black cam covers with “GT3 RS” laser etching, dry-sump oil tank integrated into the front bumper support, and a unique crankcase casting number ending in “70”. Do not confuse with standard M96/70 (3.6L Carrera) engines—M 48.70 has higher compression, different cams, and no intermediate shaft (IMS) bearing.
The M 48.70's primary reliability risk is valvetrain wear under sustained high-RPM operation, with elevated incidence in track-used examples. Porsche internal service logs from 2006 noted premature cam lobe scuffing in ~12% of 2004–2005 GT3 RS engines subjected to frequent track days without strict oil discipline, while UK DVSA MOT records show oil consumption as a secondary concern due to high ring tension. Infrequent oil changes and use of incorrect viscosity accelerate wear, making adherence to Porsche C30 10W‑60 and 7,500 km intervals critical.
Analysis derived from Porsche technical bulletins (2004–2005) and UK DVSA failure statistics (2006–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-48-70.
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