The Purest Sports Car of Its Era

When the third-generation Mazda RX-7 (chassis code FD3S) debuted in 1991, it was unlike anything else in the sports car world. While competitors relied on increasingly large and heavy engines, Mazda went a different direction: a compact, lightweight twin-turbocharged rotary engine in a body designed with obsessive attention to aerodynamics and proportion.

The result was a car that weighed just 2,800 pounds, made 255 hp (later 276 hp in JDM specification), and handled with a purity that earned near-universal praise from automotive journalists. Over a production run from 1991 to 2002, Mazda built 68,589 FD3S RX-7s, making it the rarest generation of a model that was already niche.

The 13B-REW: Engineering Marvel

The heart of the FD is the 13B-REW -- the world's first mass-produced sequential twin-turbocharged engine. The Wankel rotary motor displaces 1,308 cc (or 2,616 cc by the "equivalent displacement" method often used for comparison) and uses a sequential turbo system where a primary turbocharger provides boost from low rpm, and a secondary turbocharger joins in at higher rpm for maximum power.

The result is remarkably smooth power delivery with minimal turbo lag -- the sequential system fills the gap that a single large turbocharger would leave. In Japanese domestic market (JDM) specification, the 13B-REW produced 255 hp initially, rising to 276 hp (the gentleman's agreement ceiling) in later series.

The rotary engine's inherent advantages -- compact size, smooth operation, high-rpm capability -- allowed Mazda to mount the engine low and far back in the chassis, contributing to the FD's exceptional weight distribution and low center of gravity.

Design by Proportion

The FD RX-7's design is often cited as one of the most beautiful in automotive history. Lead designer Yoichi Sato and his team at Mazda created a body with no superfluous elements -- every surface serves an aerodynamic or structural purpose.

The car's proportions are often described as following the golden ratio, with the relationship between the front overhang, cabin, and rear creating a visual harmony that's immediately recognizable. The flowing lines, rounded headlights, and absence of sharp creases give the FD a timeless quality that has only improved with age.

At just 168.5 inches long and 48.4 inches tall, the FD is remarkably compact. It seats two and prioritizes the driving experience above all else.

The Apex Seal Question

No discussion of the RX-7 is complete without addressing the rotary engine's Achilles' heel: apex seal wear. The apex seals are small strips of metal at the tips of the rotor's triangular faces that maintain the seal between the rotor and the housing. They're the rotary equivalent of piston rings, and they wear over time.

When apex seals fail, compression drops and the engine loses power, eventually requiring a rebuild. Rebuilds typically cost $3,000-$6,000 depending on the shop and whether the rotary housings need replacement.

The reality is more nuanced than the reputation suggests. A well-maintained 13B-REW, with proper oil levels (rotary engines consume oil by design -- it's injected into the combustion chamber to lubricate the apex seals), appropriate warm-up and cool-down procedures, and regular maintenance, can last 100,000+ miles before needing attention. The cars that eat apex seals are typically those that have been neglected, modified without proper tuning, or repeatedly subjected to cold-start abuse.

What to Pay

The FD RX-7 market has appreciated significantly:

  • JDM imports (right-hand drive): $30,000-$55,000 for clean examples
  • US-spec (left-hand drive, 1993-1995 only): $35,000-$70,000
  • Low-mileage/exceptional: $70,000-$100,000+
  • Spirit R (final special edition, JDM only, 1,500 units): $80,000-$120,000+

US-spec cars command a premium because only about 13,000 FDs were sold in the US market across just three model years (1993-1995). Mazda withdrew the RX-7 from the US after 1995 due to declining sales and emissions concerns, but continued production for Japan through 2002.

Buying Tips

1. Compression test first. Before anything else, have the engine compression tested. A healthy 13B-REW should show 7.5+ kg/cm² across all faces with no more than 1 kg/cm² variation between them.

2. Service history is everything. Look for documented oil changes (rotaries need frequent changes with the correct weight oil), coolant system maintenance, and turbo service. The sequential turbo system has vacuum-operated actuators that can fail.

3. Check for modifications. Many FDs have been modified. While bolt-on modifications (intake, exhaust, boost controller) are generally fine if properly tuned, heavily modified cars carry more risk. A stock or lightly modified car is the safer purchase.

4. Inspect the turbos. Listen for whine, check for shaft play, and look for oil residue. Turbo replacement is expensive.

5. Rust inspection. FDs can rust, particularly in the rear quarter panels, wheel wells, and around the rear hatch. Southern and western US examples are preferred.

Why It Matters

The FD RX-7 is the last car Mazda built around the rotary engine as a serious sports car proposition. The RX-8 that followed was a 4-seater with a naturally aspirated rotary that, while characterful, lacked the FD's performance credentials.

In a world that has moved toward turbocharged four-cylinders and electric motors, the FD represents something irreplaceable: a sports car powered by a unique engine technology, wrapped in one of the most beautiful bodies ever designed, and weighing less than most modern hatchbacks.

The 13B-REW was an engineering dead end -- but what a glorious dead end it was.