Buick Grand National 1987 Turbo intercooled

The 1987 Buick Grand National made 245 horsepower and 355 lb-ft of torque from an intercooled, turbocharged 3.8-liter V6, with peak torque arriving at just 2,000 rpm. The intercooler that arrived for 1986 is the single component separating these cars from the largely forgettable 1984 and 1985 versions. Roughly 20,193 were built in the final model year, and the famous Lamborghini comparison actually belongs to the 547-car GNX. Read on for what to verify before buying one.

There is a particular kind of embarrassment that only happens when a car nobody respects beats a car everybody does. In 1987 Buick, a brand whose customer base skewed heavily toward people who had already retired, was selling a blacked-out mid-size coupe with a turbocharged V6 that could humiliate contemporary Corvettes and, in its ultimate form, out-accelerate a Lamborghini Countach to sixty miles per hour. It had six cylinders, a cast-iron block, and a badge most buyers associated with their grandparents. It also had one component the earliest versions did not, added for 1986, and that single part is the reason the 1987 cars are remembered while the 1984s mostly are not.

The Intercooler Changed the Argument

Buick’s turbocharged 3.8-liter V6 ran without an intercooler through 1984 and 1985, making two hundred horsepower, quick for the era but not remarkable. For 1986 an air-to-air intercooler arrived, dropping intake charge temperatures enough to allow more aggressive spark timing and higher effective boost without detonation. Output jumped to 235 horsepower, and for 1987 the Grand National was rated at 245 horsepower and 355 lb-ft of torque. Torque was always the more meaningful figure here. Peak torque arriving at just 2,000 rpm meant the car pulled hard from essentially anywhere in the rev range, which is emphatically not how anyone expected a V6 to behave in 1987.

⚑ Featured Gear

Start Car Conversations →

As an Amazon Associate I earn from qualifying purchases.

Sequential Injection and a Computer That Actually Worked

The other half of the story is electronic. The Grand National’s engine management used sequential port fuel injection and a knock sensor system that could pull ignition timing in real time when it detected detonation, which is precisely what made a boosted, cast-iron pushrod V6 survivable as a mass-market production engine. GM’s calibration work through the mid-1980s turned a powerplant that had been genuinely temperamental in the early Turbo Regals into something durable enough for ordinary owners. It is easy to forget how advanced this was in 1987, when a great many performance cars were still running carburetors or comparatively crude throttle-body injection systems.

Where the Countach Comparison Actually Came From

The famous supercar comparison belongs to the GNX, not to the standard Grand National, and the distinction genuinely matters. The GNX was a 547-car run finished by ASC/McLaren, with a larger Garrett turbocharger, a revised intercooler, unique engine calibration, a reworked rear suspension using a torque arm and Panhard rod, and fender flares covering wider wheels. Buick rated it at 276 horsepower and 360 lb-ft, figures widely understood to be conservative. Contemporary magazine testing recorded zero to sixty in the mid-four-second range. A standard 1987 Grand National sat closer to the low-to-mid five-second range, which was still enough to outrun a same-year Corvette.

Twenty Thousand Cars, One Final Year

1987 was both the last and by far the largest year for the Grand National, with roughly 20,193 built as buyers finally understood what the car actually was. That timing is characteristically General Motors. Demand peaked exactly as the platform was being retired, because the rear-drive G-body Regal ended production in December 1987 to make room for a front-drive replacement that had no provision for any of this. The turbo V6 performance program simply had nowhere to go afterward. Buick’s performance identity, which the division had spent most of a decade carefully rebuilding, evaporated in a single model-year changeover.

Grand National, T-Type, or Turbo-T

Not every black turbo Regal is a Grand National, and the trim distinctions confuse buyers constantly. The Turbo-T and T-Type shared the same intercooled engine but were available in other colors and with different trim and option content, and a well-optioned Turbo-T is mechanically identical to a Grand National in every way that affects performance. The Grand National’s specific appeal is the all-black presentation and the badge, both of which command a real premium in the market. Buyers should be reading the RPO codes on the trunk sticker rather than trusting paint and emblems, since the visual differences are straightforward to replicate.

The Sunroof Question

An astroroof was available, and it remains a genuinely divisive option among collectors. It adds weight high in the chassis, removes structural rigidity from a car that was not overbuilt to begin with, and introduces a leak path that three decades later has often let water into headliners and rear window channels. On the other hand, low-mileage sunroof cars are less common than hardtops, and some buyers value that scarcity enough to pay for it. As a practical matter, any sunroof car should be inspected carefully for evidence of past water intrusion in the trunk drop-offs and the rear seat area.

What Goes Wrong Now

The engines are robust when maintained but unforgiving when neglected. Original turbochargers eventually wear, the factory intercoolers are undersized by modern standards and prone to internal restriction, and the plastic-tank radiators of the era are long past their intended service lives. The larger issue is that these cars have been a modification target for thirty years, and a great many have been boosted well beyond factory calibration on stock internals. A car presenting as unmolested should have its computer, turbocharger, and fuel system independently verified rather than assumed, because the difference between an original 245-horsepower car and a heavily modified one is significant to value.

Why the Prices Kept Climbing

The Grand National spent the 1990s as a cheap used car and the 2000s being quietly collected by people who had wanted one when they were new and could not afford it. Clean, documented, low-mileage examples now bring money that would have seemed absurd twenty years ago, and GNXs sit in a category entirely of their own. What sustains that interest is not just nostalgia, it is that the car remains genuinely strange. A cast-iron turbocharged V6 in a Buick sedan body, beating V8 sports cars, in the year Detroit was supposedly at its lowest ebb, is a story that does not get less interesting with repetition.

What It Was Actually Beating in 1987

The competitive context makes the achievement clearer. The 1987 Corvette’s L98 small-block made 240 horsepower and needed roughly six seconds to reach sixty. The Mustang GT’s 5.0-liter was rated at 225, as was the Camaro IROC-Z with the 350. Against that field a 245-horsepower Buick sedan with 355 lb-ft available at two thousand rpm was not merely competitive, it was the quickest thing General Motors sold that year to anyone walking into a showroom. The GNX went further still. That a division associated almost entirely with comfortable highway cruisers held that position, in the final year of the platform, remains one of the odder outcomes in American performance history.

Share your thoughts in the comments below.

Republished by Blog Post Promoter