SEDONA, Arizona — Out on a long airport taxi ramp in the red rock colony of Sedona, we hurled big American luxury sedans down the tarmac to determine which is fastest from standing start to speed at 60 miles an hour.
If you tallied the number of cylinders in the engines of these competitive sedans, you might well predict winners from the outset. Two of the vehicles contained hefty V-8 powerplants, while the third drew from only six cylinders.
Yet analysis of test results revealed the fastest times, by almost a second, came from the sedan equipped with the V-6 engine — not coincidentally, the one that also produces by far the best fuel-economy figures by several miles per gallon.
How can a smaller engine beat the bigger ones? Simple answer. Supercharging.
The fastest sedan in these tests, Buick's elegant flagship Park Avenue Ultra, uses a mechanical supercharger to increase horsepower from the 3.8-liter six-cylinder engine. Before attaching the supercharger, the engine musters 205 hp. Add the supercharger and output climbs to 240 hp.
More importantly, torque generated from this horsepower — the engine's muscle used to turn the wheels — also climbs dramatically through supercharging, but at lower engine speeds, which means there's more strength available quicker through lower gears.
By applying a supercharger to a smaller engine
like the V-6 of the Park Avenue Ultra, power and torque numbers climb
significantly without adversely affecting fuel economy. And supercharging
amounts to a simple mechanical idea. Essentially, a blower driven by the engine
forces more air into each cylinder to enrich the mix of fuel and oxygen required
for combustion. This boost of air in turn generates more power with each cycle
of ignition without requiring more fuel to do so. And sometimes, in a vehicle
like the Park Avenue, supercharging makes more sense than plunking down a
Inside and all about
In 1997, the Park Avenue was redesigned for the
better. Compared to its predecessor, it measured longer in wheelbase, broader in
width and taller in stance. This bigger-taller-wider approach to automotive
design translated most significantly to more interior room in the front seat,
since head space increased by almost an inch and shoulder room grew by 1.3
inches. Rear passengers also got more room to stretch, with space for hips
increasing by another 1.5 inches and leg room enlarging by almost an
1999 Buick Park Avenue Ultra interior
The Park Avenue's roomy interior could be mistaken for some Park Avenue living rooms.
With so much improved space laced throughout the car, you might expect a hulk of a design outside, yet the lines of the Park Avenue remain similar to former versions, with a streamlined tapering prow followed by a massive windshield dramatically canted to maximize aerodynamic efficiency.
Behind the slipstream package, the revamped body structure gained structural integrity for safety, improved performance and reduced interior noise. The windshield A-pillar supports, for instance, now consist of tubular steel skewed in oval profile to magnify strength and increase visibility for a driver.
But can a big car like this behave on the road? Our road tests on mountainous routes around Sedona revealed that Buick's ultimate sedan is smooth and almost effortless, yet aggressive enough when asked.
Then came a week at home steering a Park Avenue
Ultra around city routes and freeway segments. During this time we wallowed in
the luxury of the Ultra edition. It looked good, fit a full-figured body as only
a full-size American car can, then piled on as many plush comfort trappings as
anything on the road today.
Two models split the personality
The two Park Avenue models vary primarily in power and on-board amenities, with the supercharger added to the Park Avenue Ultra. Either version links to a four-speed automatic transmission with electronically controlled shift sequences for unobtrusive transitions. This General Motors transmission, dubbed 4T65E, permits the application of more engine torque than its predecessor, which increases the floored-throttle shift point to 5700 rpm.
The base Park Avenue has a responsive power-assisted rack-and-pinion steering system, while Ultra borrows from Cadillac a Magnasteer variable-effort device that uses electronic controls for magnetic torsion to raise or lower the amount of effort required to steer. At lower speed, such as when parking, you'll feel less pressure, so the steering wheel turns easily, but at higher speed on a highway pressure increases, so only a slight movement of the wheel turns the car quickly.
Park Avenues carry power disc anti-lock brakes, dual airbags, and other safety features, all of the power and comfort figures you would expect on the finest luxury automobiles, plus GM's PASS-Key II theft-deterrent system. The Ultra sweetens its deal with more luxury gear like leather seat upholstery, automatic climate system with dual controls, analog instruments with tachometer, remote keyless entry, concert-quality stereo speakers, six-way power controls for both front bucket seats, and more.
For 1999 models, the $32,970 Park Avenue sports an improved taillamp cluster to match that of Ultra, along with an enhanced Concert Sound III sound system and, on Ultra, standard Michelin tires. Four new exterior colors include Sterling Silver Metallic, Titanium Blue Metallic, Gold Firemist and Dark Bronzemist Metallic.
The optional Gran Touring package, which raises the bar to $35,585, applies a heavy-duty suspension, programmable magnetic variable-effort steering, specific 16-inch aluminum wheels with Eagle LS Touring tires and a leather-wrapped steering wheel. An Ultra will run you $36,795.
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