The Porsche M48.50S is a 2,706 cc, flat‑six petrol engine produced between 2005 and 2008. It powered the rear-engine Porsche Cayman S (987) and featured a water-cooled architecture with an aluminum block, aluminum cylinder heads, and dual overhead camshafts (DOHC) with 24 valves. Equipped with Bosch Motronic MED 9.5.5 digital fuel injection, VarioCam Plus (variable intake and exhaust timing), and a dry-sump lubrication system, it delivered 202 kW (275 PS) and 300 Nm of torque.
Fitted exclusively to the 987-generation Cayman S and Boxster S (facelift), the M48.50S was engineered for high-revving responsiveness, track-capable durability, and refined daily driving. Emissions compliance was achieved through a close-coupled three-way catalytic converter, exhaust gas recirculation (EGR), and sequential fuel injection, satisfying Euro 4 standards under EU Directive 98/69/EC.
One documented concern is intermediate shaft (IMS) bearing wear in early M48 units, highlighted in Porsche Technical Service Bulletin TSB‑987‑2006. Although the M48 series used a larger, dual-row IMS bearing compared to the 996/997 M96/M97 engines, pre-mid-2006 builds retained a grease-lubricated design susceptible to fatigue under infrequent oil changes or extended high-RPM operation.
Production years 2005–2008 meet Euro 4 emissions standards (EU Directive 98/69/EC; VCA UK Type Approval #VCA/EMS/987S).
The Porsche M48.50S is a 2,706 cc flat‑six petrol engine engineered for the 987 Cayman S and Boxster S (2005–2008). It combines Bosch Motronic MED 9.5.5 digital injection with DOHC, VarioCam Plus, and dry-sump lubrication to deliver high-revving power and track-ready reliability. Designed to meet Euro 4 emissions standards, it balances motorsport-derived architecture with modern drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,706 cc | |
| Fuel type | Petrol (RON 98 min) | |
| Configuration | Flat-6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.0 mm × 72.0 mm | |
| Power output | 202 kW (275 PS) @ 6,250 rpm | |
| Torque | 300 Nm @ 4,500 rpm | |
| Fuel system | Bosch Motronic MED 9.5.5 sequential injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 11.3:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC with VarioCam Plus (intake and exhaust) | |
| Oil type | Porsche Longlife 0W-40 (A40 specification) | |
| Dry weight | 175 kg |
The M48.50S delivers crisp, linear power with a 7,000 rpm redline, ideal for spirited driving. Oil changes every 15,000 km (or annually) with Porsche A40 0W-40 synthetic oil are essential to protect the dry-sump system and IMS bearing. VarioCam Plus requires clean oil for hydraulic actuation—sludge or viscosity breakdown can cause timing drift. Use RON 98 fuel to prevent knock under load. Pre-mid-2006 engines should be monitored for IMS wear; post-2006 units received an oil-fed IMS bearing per TSB-987-2006, significantly improving durability.
Oil Specs: Requires Porsche Longlife 0W-40 (A40 spec) (Porsche Lubricants Guide 2006). Meets ACEA C3 but with tighter Porsche-specific requirements.
Emissions: Full Euro 4 compliance confirmed under EU Directive 98/69/EC and VCA Type Approval #VCA/EMS/987S.
Power Ratings: Measured under DIN 70020 standards. Output consistent across global Cayman S and Boxster S variants (Porsche PB-987-07).
Porsche Technical Information System (TIS): Docs PT-987-05, FT-987-06, TSB-987-2006
EU Directive 98/69/EC on vehicle emissions
VCA Type Approval Database (VCA/EMS/987S)
DIN 70020 Engine Performance Measurement Standard
The Porsche M48.50S was used exclusively in Porsche's 987 platform with rear-mounted, longitudinal orientation and no external licensing. This engine received a critical mid-cycle update—oil-fed IMS bearing from mid-2006—and all adaptations are documented in OEM technical bulletins.
Engine code M48.50S is stamped on the rear crankcase near the flywheel housing (Porsche TIS PT-987-05). The 10th VIN digit is '5' (2005), '6' (2006), '7' (2007), or '8' (2008). Visual cues: all M48.50S engines feature a black plastic intake manifold with “VarioCam Plus” labeling and twin throttle bodies. Do not confuse with 2.7L M48.30 (245 PS)—the M48.50S has larger displacement, higher compression, and unique camshafts. IMS bearing type can be verified by production date: pre-July 2006 = grease-lubricated; post-July 2006 = oil-fed per TSB-987-2006.
The M48.50S's primary reliability risk is IMS bearing wear in pre-mid-2006 units, with elevated incidence in high-mileage or infrequently serviced examples. Porsche internal data from 2007 indicated IMS-related oil contamination in under 5% of early 987s by 100,000 km, while UK DVSA records show generally robust performance compared to 996-era engines. Oil quality and change intervals make lubrication integrity critical.
Analysis derived from Porsche technical bulletins (2005–2008) and UK DVSA failure statistics (2009–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-48-50S.
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