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Monza Lab
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Monza Lab
Variant · 2011 (single model year)
The last — and largest — naturally aspirated Mezger. Porsche's 4.0L farewell to an era.
The 997 GT3 RS 4.0 was built in a single 600-unit run for the 2011 model year as the send-off for the Mezger flat-six. It took the 3.8L 997.2 GT3 RS, enlarged the displacement to exactly 3,996 cc via the 4.0 Cup/RSR crankshaft, and lifted output to 500 hp at 8,250 rpm — 125 hp per liter from a naturally aspirated road engine, with a redline beyond 8,500 rpm.
Every 4.0 was manual. Every 4.0 was produced in a calendar window of roughly six months. The global allocation was strict — approximately 141 cars for the United States and the balance distributed across Europe, the UK, Japan, the Middle East and other markets. There was no 4.0 Touring, no PDK, no second model year. The car was what it was: a one-batch limited edition intended to close the Mezger chapter before the 991 GT3 moved to the direct-injected 9A1 architecture.
The market has treated it accordingly. Clean documented 4.0s trade in the $800k–$1.3M+ band, with the best delivery-mileage cars reaching higher. It is, by broad collector consensus, the apex 997-era Porsche and the last great naturally aspirated 911 — both for what it is mechanically and for what it represents historically.
The 4.0 is the final Mezger. Porsche's motorsport-derived flat-six lineage — traceable through the 964 Turbo, 993 Turbo, 996/997 Turbo, GT2, GT3 and GT3 RS — ended with this engine. From the 991 generation onward, GT3 models used the 9A1-derived MA1/DG series. That hard technical break is why the 4.0 occupies its own category: it is the grail specifically because Porsche never built another naturally aspirated Mezger and, given current powertrain direction, never will.
Beyond the engine, the 4.0 consolidated the 997.2 GT3 RS aerodynamic and chassis package — wider front track, RS 4.0-specific front dive planes, carbon hood, lighter buckets, and a suspension tune developed on the Nürburgring. It is simultaneously the most developed Mezger chassis and the last of its kind. The combination is why market behaviour treats the 4.0 as a permanent asset rather than a cyclical one.
White body with red RS 4.0 side decals, red wheel centers. The higher-volume of the two graphics options.
White body with blue RS 4.0 side decals, blue wheel centers. Slightly less common but no material price premium in isolation.
A very small number of 4.0s were delivered in non-white factory colors (black, silver, other PTS combinations). These trade case-by-case and can carry significant premiums when well documented.
Higher-mileage (20k+ km) documented cars, original paint, clean service history
Matching numbers, original paint, low-to-moderate mileage, full books and tools
Sub-10k km, unrestored, complete provenance, single- or two-owner
Sub-1,000 km cars trade thinly; each transaction is a market data point
Non-white factory color or high-profile ownership chain can add materially
Exactly 600 units, all built in a single 2011 production batch. The US allocation was approximately 141 cars; the balance was split across Europe (Germany, UK, Italy, France and others), Japan, the Middle East and other RoW markets. There is no ambiguity about the production number — Porsche was explicit that 600 cars would be built and no more.
The 997.2 GT3 RS 3.8 (2010–2011, ≈1,800 units) is the volume RS of the generation. The 4.0 adds a larger-displacement Mezger (3,996 cc vs 3,797 cc), 500 hp vs 450 hp, higher redline, RS 4.0-specific front dive planes, carbon hood, lighter buckets, a revised chassis tune and a hard 600-unit cap. At market, the 3.8 trades $300k–$500k while the 4.0 trades $800k–$1.3M+ — a spread that reflects the displacement bump, the final-Mezger status, and the production-number delta.
The 4.0 is the last and largest naturally aspirated version of Porsche's motorsport-derived Mezger flat-six, an engine family that traces back to the 964 Turbo and 993 Turbo and underpinned every GT3, GT2 and Turbo built before the 991 generation. It produces 125 hp per liter naturally aspirated and revs past 8,500 rpm. From 991 onwards Porsche GT cars moved to the 9A1-derived MA1/DG engines — so the 4.0 is a closed chapter. Scarcity, engineering significance and irreplicability combine into grail status.
Nothing specific. The 4.0 was not a homologation car for a particular race series — the 997 GT3 R and GT3 RSR racing programs were already homologated via earlier RS variants. The 600-unit cap was a commercial and symbolic decision: a limited-edition road car marking the end of Mezger production. This distinguishes it from the 964 RS or 996 GT3 RS, which were homologation specials in the technical sense.
Porsche confirmed approximately 141 cars for the United States. The remaining ≈459 were split across global markets — Germany and the UK received the largest European allocations, Japan was a significant market, and the Middle East, Hong Kong, Singapore, Australia and Canada received smaller quantities. The US share of roughly 23% is notable given 911 GT volumes generally skew more heavily US; the 4.0 was genuinely thin in every market.
No. Every 4.0 was built with the Getrag-supplied 6-speed manual. Porsche offered PDK on the 997.2 GT3 RS 3.8 in some markets as an option, but the 4.0 was manual-only by design — part of the car's purist positioning and a factor in long-term collector demand given the broader market shift toward PDK and PDK-only GT cars that followed.
Two reasons. First, engine: it is the last naturally aspirated Mezger and, at 500 hp from 4.0 liters with an 8,500 rpm redline, the most developed. Second, era: the 991 and 992 GT3 generations are excellent cars but are built on the 9A1-derived architecture and have moved toward PDK prevalence, electronic steering and broader production. The 4.0 is the final intersection of Mezger engine, manual gearbox, hydraulic steering and single-batch scarcity — a combination Porsche has not revisited and likely will not.
The 991 GT3 RS (475–520 hp depending on generation, 9A1-derived, PDK-only) is faster on most metrics but is a different kind of car — modern, electronically richer, broader production. The 991 GT2 RS (690 hp twin-turbo, PDK-only) is a different category altogether. The 4.0 is not about lap times; it is about engine character, manual engagement and position at the end of a lineage. Values reflect that: the 4.0 trades above both in many collector contexts despite lower absolute performance.
The structural case is strong. Production is permanently capped at 600. The Mezger engine cannot be reissued given Porsche's current powertrain strategy. Manual-only, naturally aspirated GT 911s are a closing category generally. The risk is that much of this thesis is already priced in — the 4.0 has already compounded from ≈$500k in 2015 to ≈$1M+ today. Further appreciation at that pace is unlikely; preservation of value and single-digit annual compounding are the realistic long-term expectation. It is a permanent-collection asset, not a trade.
Matching numbers (engine M97/74, chassis, transmission), complete Porsche COA, build-number plaque and option-code sticker confirming RS 4.0 package, original carbon hood condition, original front dive planes (frequently damaged and replaced), suspension geometry and chassis alignment (track use is common), full service history including valve adjustments and clutch records, and a specialist PPI. At this price level, provenance gaps — missing books, unclear ownership chain, repainted panels without documentation — are material.
The 997 GT3 RS 4.0 is a permanent-collection asset with one of the cleanest structural stories in modern Porsche collecting: 600 cars, last Mezger, manual-only, single model year. The aggressive appreciation phase is past — the car already compounded roughly 2x from 2015 to 2022 — and forward returns are more likely single-digit annualized than multi-bagger. For collectors who want exposure to the end of the Mezger era and the apex 997, it is the canonical choice. Trade thinly, held long.
Back to Porsche 911 (997) buyer's guide.
Market bands are aggregated from public auction results. For the current generation-level median and YoY trend, see the Water-Cooled 911 Index.