The OG Four-Door Porsche Sports Sedan Wasn't Even Built By Porsche

Why It Matters

The story highlights Porsche’s early willingness to explore four‑door performance cars, a lineage that underpins today’s profitable Panamera and Taycan sedan lines, illustrating how niche experiments can shape long‑term product strategy.

Key Takeaways

• 1967 custom four‑door 911 built by Troutman & Barnes
• Porsche refused to stretch 911, dealer pursued independent conversion
• Conversion achieved 0‑60 mph in 6.9 seconds, 180 hp
• Pre‑Panamera shows Porsche’s long‑standing sedan collaborations
• Inspired later concepts like 928, 989, and Panamera

Pulse Analysis

The 1967 four‑door 911 S remains a little‑known footnote in automotive history, yet its creation encapsulates the inventive spirit that would later define Porsche’s entry into the sports‑sedan market. Texas dealer William Dick approached Porsche for a stretched 911, but after the factory declined, he turned to California fabricators Troutman & Barnes. They bisected a standard 911, welded sheet‑metal extensions, and installed factory doors, producing a 2,271‑pound sedan that retained the 180‑horsepower flat‑six and accelerated from 0 to 60 mph in 6.9 seconds. The project demonstrated that a pure‑sports chassis could accommodate four passengers without sacrificing performance.

Porsche’s involvement in sedan projects did not stop with the custom 911. Throughout the 1980s and 1990s the German marque supplied chassis tuning, engine development, and bodywork for the Mercedes‑Benz 500E and the Audi RS2 Avant, collaborations that blended Porsche’s handling pedigree with other brands’ platforms. Concept vehicles such as the four‑door 928 and the 989 prototype further explored the market potential of a high‑performance four‑door coupe, laying the groundwork for the Panamera’s 2009 launch. These efforts illustrate a strategic pattern: Porsche leverages partnerships and concept studies to test market appetite before committing to mass production.

Today the Panamera and its electric sibling, the Taycan sedan, generate billions in revenue and reinforce Porsche’s position beyond the iconic 911. The 1967 experiment serves as a reminder that bold, low‑volume projects can seed long‑term product lines, especially when they align with a brand’s performance DNA. For competitors, the lesson is clear: collaborating on niche platforms or creating limited‑run prototypes can uncover profitable segments without diluting core brand equity. As consumer demand for versatile, high‑performance sedans grows, Porsche’s early willingness to think beyond two doors continues to pay dividends.