From the Archive: 1979 Buick Riviera S Type Tested

From the November 1978 issue of Car and Driver.

Sixteen years ago, at the unveiling of the original Buick Riviera, Car and Driver boldly pronounced it a “new breed of American automobile” that “approaches Bentley Continental standards at less than half the price.” Grand touring is what our predecessors were raving about. Buick in­vented the all-American GT coupe, and Americans loved it. The Riv was fast and comfortable and handsome; a metal sculpture in a world of chrome-plated look­alikes. Buick made automotive history with the car, and today collectors are bid­ding close to the original prices to put them in their garages.

The vintage they’re after is the original 1963–65 117-inch wheelbase Riviera, which still stands as a golden achievement of American industrial design. In 1966, the Riviera started its tragic journey down the path of wretched excess. Like all things Detroit back then, it got longer, wider, and much heavier. This unfortunate trend con­tinued with the third-edition, boat-tailed Riv, introduced in 1971. They’re still scratching heads over this one in Flint. More than likely, we’ll never know how it all went wrong, now that Bill Mitchell’s gone off to a hard-earned retirement. He’s certainly not talking.

The fourth-edition Riviera was little more than a 1977 LeSabre with a Coke­-bottle rise to its rear fenders. Sales statis­tics prove it was a failure, but at least it had turned back toward the path of righ­teousness with 700 pounds of weight sliced out of its fat flanks.

Now, after one initial flash of brilliance followed by three restyle fiascoes, the Rivi­era is heading for its seventeenth year as Buick’s image leader. But instead of con­tinuing to live off old glories, Buick plan­ners have decided the time is right to rein­vent the great American road car. Their aim is to match the original Riviera’s pres­tige, and the opportunity has arrived with the 1979 model year. The new Riviera will be one of three new “E-car” designs from GM, in a joint development venture among Buick, Cadillac (Eldorado), and Oldsmobile (Toronado).

In most respects, this all-new chassis forges dead ahead toward 1985, when all cars big and small must do their part toward a fleet fuel-economy average of 27.5 mpg. Little has been saved from the past, and for this we can be thankful. Needless bulk, nearly a half-ton of weight, and yesterday’s styling excesses have been left behind. Oldsmobile and Cadillac did retain their front-drive technology, as well as a slight family resemblance. For Buick, it’s a fresh piece of work, and certainly the best way to begin a second career for the Riviera. But not so fresh that past success­es were ignored. There’s been a fond look all the way back to 1963 to see if some of the original Riviera magic could be in­stilled in this new rendition.

Lloyd Reuss is the visionary in Flint, Michigan—Buick Town, U.S.A.—who was charged with simultaneously looking forward and backward when it came to the new Riviera. Reuss took the helm as Buick’s chief engineer in 1975, just as crit­ical planning for the new car began. He’s a car guy—one who makes sure the “sport” is in the sport coupes, and that turbocharg­ers are earning their keep atop Buick V-6 engines. Lloyd Reuss is also the man who saved the Riviera from oblivion.

The roadable Riviera that best emulates both the original namesake and Lloyd Reuss’s intention is the S Type of this test. The S stands for “sport,” but it could just as well stand for “suspension,” because it is in roadholding that the S Type distin­guishes itself from the plain Riviera that Buick will send forth as its luxury coupe. For the S Type, the tires go from base P205R-15 radials to more purposeful GR70-15s, the shock valving and spring rates are tightened up, and fatter anti-sway bars are used to control body roll while limiting understeer. Inside, the driver is more aware of what’s going on at the road through higher-effort power steering and a genuinely supportive bucket seat.

We’ve come a long way in ride and han­dling since radial tires came into popular use, and the new Riviera is without a doubt the leading edge of GM’s achieve­ment in this area. The ride is as smooth as you’d expect it to be in a car that costs more than $10,000. But there’s also sensi­tive steering, deadeye directional stability, and no discernible front-wheel-drive feel.

The S Type will pull 0.69 g on the skid­pad, not a bad accomplishment for a car this big, and there’s more than enough roadholding to leave conventional luxury cars floundering in your wake. Amazingly enough, the Riviera doesn’t signal its trac­tion limits by falling into a crippling un­dersteer. In tight turning, you run out of cornering power about the same time you run out of horsepower, so there’s a stale­mate before maneuvers get nasty enough to chew up the tires.

If you’ve been paying attention to Euro­pean sedan advertising for the past few years, you knew there’d be handling break­throughs like this the instant an American manufacturer went to the trouble of build­ing an independent-rear-suspension (IRS) car. In truth, mounting each rear wheel at the end of its own semi-trailing arm, as Buick has done with the Riviera, does nothing to im­prove smooth-road handling. The combi­nation of body roll and rear-suspension ge­ometry forces the rear tires into camber angles that actually diminish their lateral adhesion. A radial’s grip isn’t particularly sensitive to this camber change, so the sac­rifice is slight. But it doesn’t really matter, because the rear tires aren’t the limiting factor in cornering anyway. It’s the front tires—burdened with both driving and turning forces—that invariably use up their traction first. So why even bother with IRS? For one thing, there are tremen­dous ride benefits with lower unsprung weight and decoupled rear tires, which Buick has exploited to the fullest extent. Next in importance is the fact that an IRS uses up a lot less space at the rear of the car than a rigid axle. This has allowed Buick to move rear passengers further rearward, increasing legroom substantial­ly. Also, there’s more space available for the trunk. The Riviera’s luggage capacity is now 17.0 cubic feet (with very usable length, width, and height dimensions), down only slightly from last year’s 19.8 cu­bic feet, even though 12 inches has been chopped off the overall length. Last on this list of independent-rear-suspension effects is handling. IRS keeps the rear of the car in line through chatter-bump turns, where your average rigid-axle sedan typically does a tail-first fandango toward the weeds.

So really, IRS is a do-all. American manufacturers have pleaded the cost case for years, but if IRS can be made to benefit packaging, ride, and bad-road handling, as it certainly does in the Riviera, it’s obvi­ously a worthwhile improvement.

In spite of being armed with America’s most sophisticated suspension layout, the Riviera S Type is not a front-wheel-drive, four-passenger Corvette. Far from it. Roll stiffness is low to minimize bump interfer­ence, which means you have to endure un­comfortable list angles to use all the road­holding at your disposal. Shock valving is tuned for an underdamped ride, so the Riv wallows when you try to rush it over undu­lating pavement. This is where Buick’s pri­orities come out most vividly: the Rivi­era—even in S Type trim—is first a park­-lane cruiser and second a back-road han­dler. It’s just as well because, as a built-for­-tomorrow fuel-economy special, the Rivi­era is hardly what you’d call a hard charg­er. Brute-force two-four-barrel engines and 120-mph all-day-long cruising speeds are gone forever from new cars, in case you hadn’t noticed. Buick’s fuel-economy obli­gations won’t permit installing much raw power under the Riviera’s hood, but in­stead of letting it go at that, the engineers offer an alternative. They’d like you to try a little sophistication for a change. Base power for the S Type is Buick’s turbo V-6, and the fact that a 3.8-liter engine would even be considered for a 3800-pound luxury car should tell you something about the wonderful engineering program this micro-­motor’s been through.

The V-6’s palsy was cured two years ago with the invention of an even-fire crank­shaft; its muscles were developed last year with turbocharging; and, this year, another round of refinement and retooling has been dedicated to the V-6 to make it even more socially acceptable. The whole top half of the engine—heads, intake and exhaust manifolds—is new, so the V-6 can breathe properly for the first time in its seventeen­-year history. Ports are larger and smooth­er, valves are bigger in diameter, and all passages from the cold-air intake to the tip of the tailpipe now have the capacity to draw in 43 percent more airflow and ex­haust 83 percent more spent gas. At this rate, Buick’s V-6 will be ready for Indy in a few more years, and in something more speedy than the pace car.

In the meantime, the V-6 is on line for its prestigious Riviera debut with 185 net horsepower. At least ten of these horses are a Riviera exclusive for the time being, because the front-wheel-drive layout al­lowed exhaust plumbing that’s ideal for turbocharging. Since there was room to position the turbo at the rear of the engine (rather than on top as in the Regal Sport Coupe), the left- and right-bank exhaust streams to the turbine section are almost perfectly balanced. This squeezes the most possible work out of waste exhaust energy, and also discourages flow through intake-manifold heat-riser passages (unless it’s needed after a cold start). As a result, there’s less charge heating on the induction side, less restriction on the exhaust side, and more power out the crankshaft.

Whether or not the new, improved V-6 will be judged appropriate for a big road car is yet to be seen. There are demands on the driver and compensations to be made. The turbo V-6 in our test car had a ner­vous twitch at idle that anyone brought up on well-behaved V-8s would find discon­certing. Also, the power-to-weight ratio of the Riviera with either the turbo V-6 or the normally aspirated 350-cubic-inch V-8 is depressing at best. Dial in the 2.93:1 axle ratio (2.41:1 with the 350 V-8), and you end up with acceleration that’s in the “eventually” class. Zero-to-sixty takes 10.9 seconds of patience, and a quarter-mile lasts 18.3 seconds. (If it’s any compensa­tion, these figures are quicker than those of that prestigious six-cylinder coupe from the Black Forest, the Mercedes-Benz 280CE.) Keep the red boost light on with your right foot and the Riviera will eventu­ally peak out at 105 mph, although the speedometer is X-rated above 85.

The turbo V-6 also asks you to put up with a power curve fraught with dips and sags. Accelerating from rest, the engine feels like a little V-6 up to 20 mph, where the boost indicator switches from yellow (2 psi manifold pressure), to red (over 5 psi manifold pressure). Then the pace picks up and there’s that stimulating feel of the seat pressing into your back as if two more cyl­inders just came to life. Unfortunately, the initial thrill of boost doesn’t last long, and the second-gear pull brings on a rather per­sistent detonation, as well as occasional soft spots in the power curve.

Buick engineers assure us that some spark knock during wide-open-throttle op­eration means the detonation detector is working just as it should. This device actu­ally listens for pre-ignition and signals Buick’s “Turbo Control Center” when to advance or retard ignition timing for best performance. Light knocking under boost happens to be Buick’s idea of best perform­ance, so this is part of what you have to live with in the fuel-economy-through-tur­bocharging era.

Old values die hard, and America hasn’t yet kicked its fat-torque-curve habit. Inter­estingly enough, the turbo engine does have a higher peak output than the con­ventional 350 V-8, which is the only engine alternative offered in the Riviera. Side by side in a drag race, the normally aspirated car immediately steps out to a one-car­-length lead off the line. The Turbo Riv gradually overcomes this handicap and draws even at 60 mph. Although the two never really lose sight of each other, the pressurized V-6 eventually slips into a lead because its horsepower falloff is less pro­nounced at high rpm.

Nobody’s likely to fall in love with the new Riviera for its acceleration. Fortunately, there are compensations. Even though fuel economy probably isn’t high on your list as you shop for a car in the five-figure class, it’s of more than passing interest to Buick. Gen­eral Motors must by law sell a 19-mpg (or more) fleet of cars in 1979, and Buick will do its share with small turbocharged engines wherever possible. The turbo V-6 cranks out a combined city-highway EPA rating of 19 mpg this year, compared to the 350 V-8’s 18 mpg, so you know which way Buick will be urging its customers.

Subtle prodding will not be necessary to help buyers appreciate the Riviera’s roomi­ness, however. It will no doubt go down as the most spacious four-seat car ever sold in America. The wheelbase is fairly long at 114.0 inches (the same as the Cadillac Se­ville’s), and when you add in the long, car­riage-style roof and take out all traces of a driveline hump, the Riviera gets to be quite a lovely place for four to sit for a while. (So lovely that Cadillac will build this car into a four-door in 1980 and call it the Seville.) The Riviera’s seats are chair-high and offer good support, all the way from your shoul­der blades down to the backsides of your knees. The matching bucket-seat treatment in back makes the rear compartment just as good a place to be as the front.

Good seating is only the first ingredient of the Riviera’s long-haul comfort. Its smooth roof pillars and laid-back wind­shield cut wind ruffle to an all-time low for the cars we’ve tested. Some pleasure should also come from the fact that Buick designers have applied unusually high standards of taste (for Detroit) to the Rivi­era. We’re proud to announce it doesn’t have a classically overdone boudoir interior. The velour upholstery is wrinkle-free and cropped to a low profile, and wall trimmings are keyed to function more than flash. The really stunning decoration is the instrument panel, which sweeps across the front like a solid wall of slate. The surface looks much more like a slab of rock than the piece of molded plastic it actually is, and the treatment is refreshing if only be­cause it’s not wood-grained.

There is an optional centerpiece for this mantel that should not be missed. Follow­ing Cadillac’s lead in the Seville last year, Buick will introduce a mid-year “trip mon­itor” for the Riviera. This obsoletes needle-­type instruments in one fell swoop, replac­ing both the speedometer and the fuel gauge with digital readouts. A third dis­play panel, to the right of the speedometer, comes into play as you punch up various combinations on the trip monitor’s twelve­-button keyboard. Time of day, engine tem­perature, and electrical-system voltage are the only non-trip pieces of information you can call up, and this leaves nine keys left to plot your trajectory to grandma’s house. In contrast to the Seville’s trip computer, the Riviera’s has no fuel-flow meter, so hitting the “Fuel Range” button spits out an esti­mate calculated from a consumption curve, road speed, and the amount of fuel remaining in the tank.

As its name suggests, this computer is primarily a trip device meant to keep you up to date on things like time and the dis­tance to your destination. But as long as Buick has gone to the trouble to offer an onboard microprocessor, we’d like to see it developed into a serious scientific instru­ment for those road pilots who really ap­preciate a gizmo like this. It could be wired with readouts on oil pressure, oil tempera­ture, engine rpm, instantaneous fuel econo­my, turbo boost pressure, turbine rpm, and exhaust temperature. If we can’t go fast in our road cars anymore, why shouldn’t we have as much fun as possible going slow?

This seems to be Buick’s general attitude with the Riviera S Type anyway. It’s an attitude that’s delivered us a car with all the sophistication and most of the per­formance of some highly revered automo­biles: the Saab Turbo, the Mercedes-Benz 280CE, and the Volvo 262C. What the Riviera lacks in fun-to-drive roadability next to these cars, it more than makes up in comfort. So sixteen years later, the Rivi­era has regained a niche as prestigious as its starting point. Our predecessors would no doubt have concluded that it ap­proaches Mercedes-Benz 280CE standards at less than half the price.

Source: Reviews - aranddriver.com