From the February 1981 issue of Car and Driver.
It is safe to say that the new S-class Mercedes-Benz cars—380SEL and 300SD in the United States—are a critical success. They’ve been well received by the motoring press (Car and Driver, November 1980), and the public’s reaction seems to be a positive one as well. Certainly the new cars look better. They’re sleeker, smoother, better-integrated designs from bumper to bumper. This is a natural result of the very heavy emphasis on improved aerodynamic performance that was the main thrust of their development, along with a significant reduction in weight. Both of those goals were achieved, the net-net being worthwhile increases in fuel economy for both diesel and gasoline models. The gasoline-powered 380SEL, unfortunately, has lost the performance that made its 450SEL predecessor such a joy to drive; although there is an improvement in its zero-to-sixty time, it is slower from there on up, and the top speed has been lopped off by twenty miles per hour. On the other hand, the turbocharged five-cylinder diesel 300SD is faster than the car it replaces, which should add to the already burgeoning public enthusiasm for what must surely be the most expensive fuel efficiency in the entire fuel-frightened Western World.
The 300SD is powered by the 2998-cubic-centimeter, overhead-cam, five-cylinder inline turbo-diesel engine that Mercedes-Benz introduced in this country in 1978. It is an engine as yet unavailable to European Mercedes buyers, developed to enhance the appeal of diesel-powered cars to American buyers and thus help Mercedes—which has no line of small ultra-efficient cars—to meet the U.S. corporate average fuel-economy standards. It worked, and the percentage of diesel-powered Mercedes sold here goes up every year. This engine now produces 120 horsepower at 4350 rpm—ten more than when it was introduced—thanks to a higher-lift camshaft. Better yet, it produces 170 pounds-feet of torque at 2400 rpm, not that much less than the gasoline-powered 380SEL, and this torque is put to most effective use by a new four-speed automatic transmission, delivering zero-to-sixty times on the order of twelve seconds. Damned good, for a diesel.
The price is almost impossible to explain or justify, and one falls back on hard-to-quantify attributes like “feel” and “character” to make this seem like a prudent purchase. The standard equipment list helps a little, but the roster of features it describes isn’t that different from cars costing less than half the price. Automatic climate control, automatic transmission, cruise control, power windows, electrically heated rear window, first-aid kit, halogen headlights and fog lamps, power steering and four-wheel disc brakes, steel-belted radials on alloy wheels, Becker Europa AM/FM-stereo/cassette system with automatic antenna, electrically adjustable right-hand mirror, rear reading lights, electrically adjustable front seats (with perhaps the slickest eight-way adjustment system ever devised for an automobile), tinted glass, vinyl upholstery (cloth or leather available at extra cost), quartz chronometer, illuminated vanity mirrors, a useful third visor that keeps the sun from burning in over the top of the rear-view mirror, and plasticized undercoating. It all goes together harmoniously, if not stunningly.
The new 300SD also has this terrific new central-locking system. No longer relying on engine vacuum for operation, it locks all four doors, the trunk, and the gas-filler flap with a little electrical pump in the luggage compartment. This guarantees that you’ll always be able to twist the key in the driver’s door and see all those little locking buttons rise in unison, vacuum or no vacuum.
So why was I standing in the freezing cold in Thermopolis, Wyoming, cursing a new S-class 300SD with an inoperative central-locking system? “Unlock the doors manually, twit,” is your natural response to my dilemma, right? Well, it’s more complicated than that. We can unlock the doors manually, and the key will override the trunk lock, but we can’t get the filler flap open. “Check the fuses,” you say. Okay, but there’s no owner’s manual in this car and I’m not sure where the fuses are. “Probably under the hood.” Well, that’s another problem. We can’t get the hood open either, and the nearest Mercedes-Benz dealer is so far away that people just laugh when you ask about him.
Suffice it to say that while I called for advice, my co-driver hooked her purse strap around the hood-release lever, planted her feet firmly on the ground beside the car, and heaved for all she was worth. The hood popped up. That revealed the fuse box, but the problem wasn’t the fuse. The tank on the little electric pump wasn’t holding pressure. On a hot streak, the aforementioned co-driver then took her trusty Swiss Army knife and worried the little latch back until it cleared the filler flap, and we were able to load up on Diesel Number Two and continue the journey. A lady friend in Sun Valley pointed out that we could put a drop of water into the latching mechanism and it would freeze, thus rendering the lock inoperative and allowing us to get fuel anytime we wanted to. It should be clear from all this that women are intellectually superior to at least one man who shall remain nameless, and that our Mercedes 300SD test car wasn’t quite up to the traditional Mercedes-Benz standard.
Make no mistake, the new S-class Turbo Diesel is a superior car in most areas, but perhaps not the paragon of automotive virtue that one might expect when the opening bid is $34,185. The engine on our test car seemed awfully noisy, for one thing. And resistance to crosswinds wasn’t as good as in earlier 300SDs, for another. And finally, it wasn’t a very nice car to drive on ice and snow—demonstrating a tendency to snap loose unpredictably at odd moments when the torque curve and the transmission ratio would cross at some critical point. Some of this may have been due to the Pirelli P3 tires, evidently specified by the maker as a cost- and weight-saving measure. On a 175-mile trip through a blizzard, accompanied by a little front-wheel-drive Dodge Colt, the 300SD was definitely the least reassuring of the two. But outside the city limits of Thermopolis, Wyoming, and driven on anything but minimum-coefficient snow and/or ice, the 300SD was a charmer. It’s hard to describe the thrill of actually blowing off other late-model cars away from stoplights in a diesel! They can’t believe it either. You look over at the guy in the Buick LeSabre V-6, the light changes, and you leave him groping his way through your dense cloud of brown smoke. Ecstasy, diesel division.
Specifications
Specifications
1981 Mercedes-Benz 300SD
Vehicle Type: front-engine, rear-wheel-drive, 5-passenger, 4-door sedan
PRICE
Base/As Tested: $34,185/$35,758
ENGINE
turbocharged inline-5 diesel, iron block and aluminum head, port fuel injection
Displacement: 183 in3, 3000 cm3
Power: 120 hp @ 4350 rpm
TRANSMISSION
4-speed automatic
DIMENSIONS
Wheelbase: 115.6 in
Length: 202.5 in
Curb Weight: 3840 lb
C/D TEST RESULTS
60 mph: 12.1 sec
1/4-Mile: 18.7 sec @ 73 mph
Top speed: 102 mph
Braking, 70–0 mph: 204 ft
Roadholding, 282-ft Skidpad: 0.70 g
C/D FUEL ECONOMY
Observed: 23 mpg
EPA FUEL ECONOMY
City: 26 mpg
C/D TESTING EXPLAINED