what’s the difference between the grand national and the gnx?
Great question! The GNX (the ‘X’ stands for “Grand National Experimental”) is essentially a supercar-grade evolution of the Grand National, built in partnership with ASC/McLaren Performance Technologies as a special send-off for 1987.
Here are the key differences:
Performance & Engineering: The ‘87 Grand National already has a stout 3.8L turbo V6 with 245 hp and 355 lb-ft of torque—plenty quick! But the GNX takes things much further. ASC/McLaren swapped in a larger Garrett T-3 turbo with a ceramic impeller for quicker spooling, a more efficient intercooler, less restrictive exhaust, and a custom-programmed computer. Buick officially claimed 276 hp and 360 lb-ft, but in reality these cars made over 300 hp and a massive 420 lb-ft of torque. That’s enough to hit 0-60 in about 4.6 seconds versus the GN’s 6.1 seconds—fast enough to embarrass Ferraris and Corvettes of the era.
The GNX also got a completely reworked rear suspension with a ladder bar and Panhard rod to put all that power to the pavement without wheel hop—something the standard GN struggled with under hard acceleration.
Visual Differences: At a glance, both are all-black coupes, but the GNX has subtle telltales:
Rarity & Value: This is where it gets interesting from a collector perspective:
So the GNX is essentially a low-production, factory-tuned supercar-killer that commands a massive premium today. The good news? The Grand National you’re looking at is still a fantastic car with the same sinister blacked-out look and plenty of turbo punch!
Learn more about the markets:
Would you like me to see if there are any GNX vehicles currently available for sale, or do you have more questions about the Grand National you’re looking at?
