Chevrolet
Corvette SS (XP-64)

Why it matters

The Corvette SS was Chevrolet's only purpose-built factory racing car of the 1950s, an all-Chevrolet project that Zora Arkus-Duntov was assigned in October 1956. It was meant to take on Ferrari, Jaguar and Maserati at Sebring and Le Mans, but the AMA ban on factory racing in June 1957 ended the program after a single race.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Each kind of rarity is rated separately and never combined.

Photos

Exterior, interior and detail photos with their licences.

• Chevrolet Corvette SS (XP-64) (Wikimedia Commons: Chevrolet Corvette SS)
  Photo: Charles · CC BY 2.0
• Chevrolet Corvette SS (XP-64) (Wikimedia Commons: Chevrolet Corvette SS)
  Photo: Charles · CC BY 2.0
• Chevrolet Corvette SS (XP-64) (Wikimedia Commons: Chevrolet Corvette SS)
  Photo: Charles from Port Chester, New York · CC BY 2.0
• Chevrolet Corvette SS (XP-64) (Wikimedia Commons: Chevrolet Corvette SS)
  Photo: The359 · CC BY-SA 3.0

Production

Every figure says what it counts.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

Two cars were built: the finished competition and display car and a minimally bodied development car known as "The Mule". The SS went from drawing board to track in about five months and arrived at Sebring on 22 March 1957, the day before the 12 Hours. Driven by John Fitch and Piero Taruffi, it started first on the engine-size grid but retired after 23 laps with brake, suspension and cockpit-heat problems. Fangio and Moss lapped Sebring faster than the 1956 lap record in the Mule during practice.

After the AMA decision of 6 June 1957 the program ended. The SS stayed with General Motors, made show appearances and test runs by Arkus-Duntov at Daytona and Mesa, and was donated to the Indianapolis Motor Speedway Museum in 1967. The Mule chassis was acquired by Bill Mitchell and became the basis of the XP-87 Stingray Racer.

The car was titled in 2002, had its engine replaced after a failure in 2014 and sold at RM Sotheby's Miami in 2025 for $7,705,000.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

Identification guide

How to tell an original from a replica or later conversion.

Distinguishing features are the tubular chrome-molybdenum truss frame, the magnesium body hinged at front and rear, the plastic canopy, the toothed grille and the finned aluminum front brake drums. The car was given a state title with the VIN MVIN215923IND on the firewall in 2002. The museum found in 2014 that the engine fitted was a 1959 unit, replaced by a new-old-stock 1957 engine.

Sources

Each number links to the exact facts it supports.

1. 1
   RM Sotheby's – 1957 Chevrolet Corvette SS Project XP-64 (Miami 2025) Level B

   • 2 Corvette SS chassis built: one finished magnesium-bodied race car and one test car/prototype ('the Mule')

   Accessed 2026-11-12
2. 2
   1957 Chevrolet Corvette SS (Project XP-64), Miami 2025, Lot 107 Level C RM Sotheby's

   • standard 283-cubic-inch V-8 block
   • bore and stroke of 3.875 inches by 3.0 inches
   • aluminum cylinder heads with solid lifters
   • Chevrolet's Ramjet fuel injection system
   • output of over 300 horsepower
   • aluminum four-speed close-ratio gearbox
   • four-speed
   • final drive was set to 3.55:1
   • frame weighed in at just 180 pounds
   • Independent suspension was implemented at the front
   • rear featuring a de Dion setup
   • unique front and rear drum brake system
   • final steering ratio of 12:1
   • body was constructed in lightweight magnesium
   • The SS weighed in at 1,850 pounds dry
   • achieving a top speed of 183 mph
   • 43-gallon plastic fuel tank

   Accessed 2026-11-12