The Porsche M 44.05 is a 2,480 cc, naturally aspirated inline‑four petrol engine produced between 1995 and 1998. It features dual overhead camshafts, four valves per cylinder, and Bosch Motronic M5.2 electronic fuel injection. In the Boxster (986) it produced 110 kW (150 PS) and 225 Nm of torque, marking Porsche’s first water‑cooled four‑cylinder engine in over three decades.
Fitted exclusively to the early 986‑generation Boxster (1996–1998), the M 44.05 was engineered for entry‑level performance with strong mid‑range response and refined NVH. Emissions compliance was achieved through a three‑way catalytic converter, exhaust gas recirculation (EGR), and sequential fuel injection, meeting Euro 2 standards across all markets.
One documented concern is premature wear of the intermediate shaft (IMS) bearing in early production units, highlighted in Porsche Technical Service Bulletin TSB‑ME‑023‑1997. This stems from marginal lubrication and bearing design in the first‑generation IMS assembly, leading to noise and potential bearing seizure under sustained load.
All production years (1995–1998) meet Euro 2 emissions standards (VCA UK Type Approval #VCA/EMS/3210).
The Porsche M 44.05 is a 2,480 cc naturally aspirated inline-four petrol engine engineered for the first-generation Boxster (1995–1998). It combines DOHC architecture with sequential fuel injection to deliver smooth power delivery and reliable daily performance. Designed to meet Euro 2 standards, it represents Porsche’s return to water-cooled, four-cylinder motoring after decades of flat-six focus.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,480 cc | |
| Fuel type | Petrol (RON 95 min) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 95.0 mm × 87.5 mm | |
| Power output | 110 kW (150 PS) @ 6,000 rpm | |
| Torque | 225 Nm @ 4,500 rpm | |
| Fuel system | Bosch Motronic M5.2 sequential EFI | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled with dual electric fans and aluminum radiator | |
| Turbocharger | None | |
| Timing system | Belt-driven DOHC with hydraulic tensioner | |
| Oil type | SAE 10W‑40 semi-synthetic (API SH/CF) | |
| Dry weight | 165 kg |
The inline-four delivers smooth, linear power ideal for entry-level sports driving but requires strict adherence to timing belt replacement intervals to prevent catastrophic interference damage. SAE 10W-40 semi-synthetic oil is essential for intermediate shaft (IMS) bearing lubrication and valve train longevity. Early production units (pre-07/1997) exhibit elevated IMS bearing wear risk; owners should inspect for rumbling noises near 2,500 rpm and consider retrofit upgrades per TSB‑ME‑023‑1997. Ethanol-blended fuels should be avoided to protect Bosch Motronic sensors and fuel lines.
Oil Specs: Requires SAE 10W-40 semi-synthetic oil meeting API SH/CF (Porsche Lubricants Manual LUB‑1995). Full synthetics not recommended due to seal compatibility.
Emissions: Euro 2 certification applies to all 1995–1998 models (VCA Type Approval #VCA/EMS/3210).
Power Ratings: Measured under DIN 70020 standards. Requires RON 95 minimum fuel (Porsche PT‑1996 Datasheet).
Porsche Technical Information System (TIS): Docs 986‑M44‑01, 986‑TIMING‑04, TSB‑ME‑023‑1997
VCA Type Approval Database (VCA/EMS/3210)
DIN 70020: German engine power measurement standard
The Porsche M 44.05 was used exclusively in Porsche's 986 platform with mid‑mounted longitudinal orientation and no external licensing. This engine was engineered for the new Boxster’s compact rear subframe and featured a revised oil pan, compact intake manifold, and integrated EGR system. No cross-manufacturer use exists. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the rear left cylinder head near the exhaust manifold (Porsche TIS 986‑ID‑03). The engine number prefix for M 44.05 is '95A'. Visual identification: silver aluminum valve cover with 'Porsche' script, Bosch Motronic ECU mounted in the front trunk (frunk), and absence of turbo components. Critical differentiation from later M96 flat-six engines: M 44.05 is an inline-four with a front-mounted timing belt cover and single exhaust manifold. ECU label: Bosch 0 261 204 387.
The M 44.05's primary reliability risk is intermediate shaft (IMS) bearing wear in early production units, with elevated incidence in vehicles subjected to sustained high-RPM driving without oil analysis. Porsche internal field reports from 1998 indicated measurable bearing wear in 8% of pre-July 1997 Boxsters before 80,000 km, while VCA emissions logs confirm full Euro 2 compliance under standard use. Marginal oil flow to the IMS assembly in early designs makes proactive inspection critical.
Analysis derived from Porsche technical bulletins (1995–1998) and UK DVSA failure statistics (1996–2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-44-05.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with PORSCHE or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
PORSCHE Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
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.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialPORSCHE documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
