Buick GNX
Photo: ilikewaffles11, CC BY 2.0, via Wikimedia Commons
Vehicles · Vintage American Muscle
Buick GNX · 1987
The blacked-out send-off for Buick's rear-drive Regal: a turbocharged, intercooled 3.8-liter V6 finished by ASC/McLaren with flared fenders, fender vents, a torque-arm rear axle and a dash-top boost gauge. Rated at a deliberately modest 276 hp, it out-ran the 1987 Corvette and Ferrari's contemporary V8s to the quarter-mile — the fastest US production car of its year.
The one to have: Sub-1,000-mile, documented GNX — 1 of 547, with build sheet, window sticker and ASC/McLaren paperwork.
Specification
Engine
3.8L turbo V6
Intercooled; Garrett T3 with ceramic turbine (231 cu in)
Output
276 hp / 360 lb-ft
Factory-underrated; independent tests showed 300+ hp
0-60 mph
4.7 sec
Quarter mile ~13.4 s at 102 mph (164 km/h)
Built
547
All black, all 1987; converted from Grand Nationals by ASC/McLaren
The market
Verified sales on file
3
May 2025 – Sep 2025
Median sale
$242k
all tracked results
★ Delivery-mile GNX
$248k
median of 2 target-spec sales
Top result
$255k
Bring a Trailer · Aug 2025
Benchmarks: Documented low-mile cars $230k–$255k; higher-mile drivers $130k–$180k. · Trend: Strong; low-mile cars near records
Know the real one
Identity tell: GNX-only fender vents, flared arches, 16-inch mesh wheels and a Stewart-Warner analog gauge pod atop the dash; each carries an ASC/McLaren build plaque.
Production reality: exactly 547 built, every one black, every one a 1987 Grand National sent to ASC/McLaren for conversion.
Spotting a lesser car: a Grand National is not a GNX — verify the ASC/McLaren serial plaque, the fender flares/vents and the gauge package; 'GNX-look' Grand Nationals are common.
The spec that matters: intercooler, ceramic-turbine T3 and a prepared 200-4R made it the quickest US production car of 1987.
Verified sales · ★ = target spec · foreign results converted to USD as noted
| Date | Venue | Year | Spec | Miles | Price | Loc | Note |
|---|---|---|---|---|---|---|---|
| Sep 2025 | Bring a Trailer | 1987 | GNX #119/547 ★ | 584 | $242,000 | — | Delivery-wrapped mats and passenger seat; time-capsule preservation |
| Aug 2025 | Bring a Trailer | 1987 | GNX #326/547 ★ | 843 | $255,000 | — | Low-mile documented car; among the year's top results |
| May 2025 | Bring a Trailer | 1987 | GNX #274/547 | 2,200 | $230,000 | — | No-saled at $142k in 2024; 33 bids in final 27 minutes to $230k |
Where to hunt
Bring a Trailer — GNX resultsSold-listing archive, the volume market
Classic.com — Buick GNX marketAggregated sales, median and trend
Glenmarch — Buick GNX resultsCross-house auction archive
Research file — market data verified through July 18, 2026.
Sources: individually observed results via Classic.com feeds, BaT, Cars & Bids, Mecum, RM Sotheby's,
Broad Arrow, Gooding, Collecting Cars, PCARMARKET and venue coverage, plus marque registries and factory press material.