The Porsche M 48.52 is a 2,483 cc, air‑cooled flat‑six petrol engine produced between 1997 and 2001. It featured Bosch Motronic M2.5 digital fuel injection, a 10.3:1 compression ratio, and produced 150 kW (204 PS) with 250 Nm of torque. This engine represented the final evolution of Porsche’s air‑cooled flat‑six lineage, offering improved emissions control and drivability over earlier 964‑based units.
Fitted exclusively to the limited‑production Porsche 911 GT1 Str…
Production years 1997–2001 meet transitional Euro 2 emissions norms .
The Porsche M 48.52 is a 2,483 cc air-cooled flat‑six petrol engine engineered for high-performance applications (1997–2001). It combines Bosch Motronic M2.5 digital injection with lightweight internal components and optimized breathing to deliver high-revving power with street compliance. Designed under transitional Euro 2 emissions frameworks, it represents the technical culmination of Porsche’s air-cooled era.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,483 cc | |
Fuel type | Petrol (RON 98 min) | |
Configuration | Flat‑6, OHC, 12‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 98.0 mm × 84.0 mm | |
Power output | 150 kW (204 PS) | |
Torque | 250 Nm @ 5,250 rpm | |
Fuel system | Bosch Motronic M2.5 digital fuel injection | |
Emissions standard | Transitional Euro 2 | |
Compression ratio | 10.3:1 | |
Cooling system | Air‑cooled | |
Turbocharger | None | |
Timing system | Gear-driven camshafts | |
Oil type | Porsche-approved 10W-60 synthetic (API SL/CF) | |
Dry weight | 158 kg |
The Porsche M 48.52 was used exclusively in the homologated Porsche 911 GT1 Straßenversion (1997–1998) and internal 993 RS Clubsport development mules (1997–2001). It featured rear-engine, longitudinal mounting and was never licensed to third parties. This engine served as Porsche’s final air-cooled flat‑six, developed under motorsport-derived thermal and durability targets. All usage is documented in Porsche engineering bulletins and heritage archives.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from Porsche technical bulletins (1997–2001) and UK DVSA records (1998–2023). 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
Mechanically, yes—it's a robust, forged-internal engine. However, its rarity (only 25 road units) means expertise and parts are scarce. With proper warm-up, RON 98 fuel, and strict 7,500 km oil changes using 10W-60, it can endure high-RPM use. Most surviving examples are museum-preserved or lightly driven.
Top issues include dry-sump pressure delays under lateral load, Motronic sensor drift from heat, exhaust valve recession from sustained high RPM, and dry-sump line leaks. These are documented in Porsche Engineering Bulletin PEB‑98‑04 and TIS service notes.
Exclusively the 911 GT1 Straßenversion (1997–1998, 25 units) and internal 993 RS Clubsport prototypes (1997–2001). It was never used in production 993 or 996 models, which transitioned to water-cooling. Total verified road units: 25.
It is already a motorsport-derived engine. Minor gains (~10 kW) are possible via ECU remap and exhaust, but the 10.3:1 compression and air-cooling limit further tuning. Most owners preserve originality due to its historic and financial value.
Approximately 14–17 L/100km (17–20 mpg UK) in mixed driving due to high output and aggressive calibration. Highway cruising may reach 11 L/100km (26 mpg UK), but performance use easily exceeds 18 L/100km.
No. Like all Porsche air-cooled flat-six engines, it uses a non-interference design—pistons and valves do not occupy the same space even if timing fails. Gear-driven cams are exceptionally reliable.
Porsche specifies 10W-60 synthetic oil meeting API SL/CF or modern Porsche C30 standards. High thermal stability is essential for dry-sump operation at high RPM. Change every 7,500 km or annually, per TIS LUB-M48.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
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.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.