The Porsche M 44.08 is a 2,480 cc, naturally aspirated inline‑four petrol engine produced between 1996 and 2000. It features dual overhead camshafts (DOHC), 16 valves, and Bosch Motronic M5.2 engine management. In standard form it delivered 110 kW (150 PS) at 5,800 rpm with torque of 220 Nm at 4,200 rpm, engineered for smooth power delivery and refinement in entry-level Porsche applications.
Fitted exclusively to the Porsche Boxster (986) from 1996 to 1999 (model year 1997–1999), the M 44.08 was designed to offer accessible performance with strong mid-range response and compact packaging. Emissions compliance was achieved through a closed-loop lambda system and catalytic converter, meeting Euro 2 standards across European markets.
One documented engineering concern is intermediate shaft (IMS) bearing wear in early production units, highlighted in Porsche Technical Service Bulletin 986‑01‑99. While not as severe as later M96 flat-six IMS issues, pre‑mid‑1997 M 44.08 engines used a non-serviceable IMS bearing that could degrade over time under high thermal stress. From June 1997, Porsche revised the IMS bearing design to a larger, more robust unit with improved lubrication.
All production years (1996–2000) meet Euro 2 standards (TüV Germany Type Approval #TUEV/EMS/4408).
The Porsche M 44.08 is a 2,480 cc inline‑four naturally aspirated petrol engine engineered for the first-generation Boxster (1996–2000). It combines DOHC architecture with Bosch electronic fuel injection to deliver linear power and compact rear-mid mounting. Designed to meet Euro 2 emissions, it balances driver engagement with regulatory compliance for its era.
| 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) @ 5,800 rpm | |
| Torque | 220 Nm @ 4,200 rpm | |
| Fuel system | Bosch Motronic M5.2 with sequential injection | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.2:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain‑driven DOHC with hydraulic tensioner | |
| Oil type | Porsche A40 (SAE 10W‑40) | |
| Dry weight | 142 kg |
The M 44.08 provides smooth, linear power ideal for balanced road handling but requires strict adherence to 10,000 km or 12-month oil change intervals to maintain IMS bearing and timing chain health. Porsche A40 (10W‑40) oil is critical due to its specific additive package for older engine architectures. Early units (pre-06/1997) use a smaller IMS bearing prone to wear under sustained high-RPM use; post-June 1997 engines feature an upgraded bearing. Valve clearance should be checked every 60,000 km as solid lifters require periodic adjustment.
Oil Specs: Requires Porsche A40 (10W‑40) specification (Porsche SIB 986‑01‑99). Equivalent to ACEA A3/B3 with Porsche-specific shear stability requirements.
Emissions: Euro 2 certification applies universally (TüV Germany Type Approval #TUEV/EMS/4408). No Euro 3 compliance for this engine series.
Power Ratings: Measured under DIN 70020 standards. Full 150 PS output requires RON 95 fuel and proper valve clearance (Porsche TIS Doc. 986‑P01).
Porsche Technical Information System (TIS): Docs 986‑E10, 986‑F05, 986‑C01, SIB 986‑01‑99
TüV Germany Type Approval Database (TUEV/EMS/4408)
DIN 70020: Motor vehicle power measurement standards
The Porsche M 44.08 was used exclusively in Porsche's 986 Boxster platform with rear‑mid longitudinal mounting and no external licensing. This engine received minor running updates—revised IMS bearing from mid‑1997 and updated ECU mapping in 1998—creating interchange considerations. No partnerships existed with other manufacturers. All adaptations are documented in OEM technical bulletins.
Engine code M 44.08 is cast into the front of the engine block below the exhaust manifold (Porsche TIS 986‑E10). VIN 7th digit is 'B' for base Boxster; 10th digit '7'–'9' denotes 1997–1999 model years. Early engines (build date <06/1997) have part number 986.100.101.00 and use a smaller IMS bearing (28 mm). Revised engines use part number 986.100.102.00 with 32 mm IMS bearing. Do not interchange cylinder heads from later M96 flat-six engines—the valve train and coolant passages are incompatible despite visual similarity.
The M 44.08's primary reliability concern is early-production IMS bearing wear in pre-June 1997 units, with elevated incidence in high-mileage or track-used vehicles. Porsche internal service data from 1999 indicated a subset of early Boxsters required IMS inspection before 100,000 km, while no crankshaft or block failures have been reported. Thermal cycling and oil change discipline make fluid quality critical.
Analysis derived from Porsche technical bulletins (1996–2000) and TüV Germany failure statistics (1997–2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-44-08.
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