THE WORLD'S GREATEST SEDAN? Mmmmm, that's big talk. Not like Road & Track. We're more likely to say "One of the world's greatest sedans" rather than the world's greatest sedan. So what is it about the 6.3-liter Mercedes-Benz 300SEL that sends us off in such raptures? Actually, like all cars that qualify as great cars, it isn't any one particular thing but a whole combination of outstanding characteristics that make it add up to something extra special.
So what is this remarkable vehicle? Basically it's the 300SEL equipped with the 6.3-liter V-8 instead of the latest 2.8-liter 6. The overall package is an excellent size for use in this country; 112.2 in. wheelbase and 196.9 in. overall length. This is a 4-in. stretch on the 280 M-B sedan series, making a worthwhile difference in legroom but not enough to make it feel like an aerobus. Compared with American sedans, it's about a foot longer than a Detroit ponycar and about two feet shorter than a typical luxury sedan.
The engine. which is also used in the 600 sedan and limousine, is a single-overhead-cam V-8, fuel-injected and conservatively rated by the manufacturer at 300 bhp at 4100 rpm. This is coupled to a 4-speed automatic transmission and drives the rear wheels through a limited-slip differential and typical M-B low-pivot swing axles. The suspension is the same as that of the 300SEL; that is, air-bag springs with built-in self-leveling (as well as a "high" setting that gives two more inches ground clearance) instead of the metal springs used in the smaller (and less expensive) models. Otherwise, the suspension is conventional M-B with unequal A-arms and an anti-roll bar at the front and swing axles with trailing arms at the rear. There are vented disc brakes on all wheels and these, like the steering, are power assisted.
In appearance, it says Mercedes and nothing else. The styling is conservative, there isn't a frill or a furbelow anywhere, and the wheel covers are simply wheel covers and haven't been "styled" to imitate flying saucers, turbine rotors or anything else. There are just the barest clues that this is some kind of special Mercedes a "6.3" trim piece on the rear and big fat Dunlop SPs.
Inside, it's luxurious but not oppressively so. The upholstery is genuine leather, the paneling on the dashboard is genuine wood, the carpeting is high quality, there are pull-down arm rests in front and back, there are useful parcel nets behind the front seats, there is not a vanity mirror behind the passenger's sunvisor (curious) and all the window switches and other actuating devices are safety-shielded. The air conditioning is neatly integrated into the dash (so neatly and unobtrusively that a couple of casual drivers didn't know there was air conditioning) and everything has the air of unostentatious good taste and solid workmanship that you'd expect. The typical Las Vegas resident would undoubtedly prefer a white Cadillac, but that says more about the typical Las Vegas resident than the quality of the two cars, don't you think?
There are several nice mechanical touches that set it aside from most lesser cars. It has a vacuum-operated automatic door-locking feature which, when the driver's door is locked, causes all the other doors and the trunk to lock themselves. The radio antenna automatically extends and retracts itself when the radio is turned on or off. The seats have a 3-way adjustment range-fore and aft in the usual manner, lean-back in the usual manner, and a tilting track for the seat bottom which allows you to select the most comfortable angle and seat height. But it isn't gadget-ridden; you still sit behind a business-like steering wheel, looking out over a business-like hood, with proper round instruments positioned high on the dashboard so you have a good view of them. So Mercedes hasn't made the mistake of forgetting that they're building an automobile and that automobiles are for driving. not womb-substitutes or ladies' powder rooms.
So what makes it so great? Simply that whatever it is asked to do, it does better than almost any other car. The size, as noted earlier, is right; neither so small that you feel intimidated nor so large as to be clumsy. The shape of the body is also right, as you can see the extremities from the driver's seat and this inspires confidence not only in parking but in every kind of driving. The handling is excellent by any standards; not only is it far superior to any other sedan you can name but better than most sports cars. It has brakes so good you have to experience them to appreciate them. We got a deceleration rate of 96%-g on our panic stop from 80, tremendous for a 4000-lb sedan, and in our 6-stops-from-60 fade test, the last stop was as smooth, straight, true and unfussed as the first. The automatic transmission a 4-speed planetary gearbox with a fluid coupling though not as buttery smooth as, say, Cadillac's Turbo Hydra-Matic, is positive in action and offers a considerably greater degree of driver controllability. The power assists on the brakes and steering are not overdone, as on almost all American cars retaining a good degree of "feel" and, consequently, control. The steering is also commendably quick at only three turns lock-to-lock.
The low-speed ride of the 300SEL 6.3 is not dead smooth and silent as the inherent harshness of the radial-ply tires and the firm suspension conspire to keep you in touch with the small irregularities in the road surface. In this respect, the typical American sedan is quieter and more completely insulates its occupants from such irregularities. The 6.3 is far better controlled over major bumps and dips, though, has a far superior ride without sway or bobbing at highway speeds and on indifferent or poor surfaces really shows its superiority. On rough roads, the 6.3 is simply miles and years ahead of anything built in the U.S. . . . and most of Europe. We drove it over a very wide variety of roads and even on the most uncomfortable kind of washboarded gravel, the suspension worked, the wheels stayed on the ground and it behaved superbly.
But the one single characteristic of the car that makes the 6.3 outstanding even among Mercedes is, you're right, the power! We like Mercedes cars and it's a tribute to our appreciation that there are more M-Bs, on the staff than any other single make of car. But in every one of the lesser Mercedes, we've always felt just a little apologetic for the lack of power. Or the lack of easy, effortless power. Not in the 6.3. In our standard acceleration tests we were able to perform 15.1-sec standing quarter-miles with complete ease and only one manual shift. The factory claims 14.25-sec quarters with this rear end ratio but our test car would not do it, even with only the driver aboard.
We enjoyed the drag racing aspects of the 6.3 so much that we even took it to Orange County International Raceway for a "grudge race" night. As luck would have it, there was such a crowd that we could only get three runs during the evening but we won two and were finally put down by a 427 automatic Corvette. (The fact that the Corvette was driven by a girl and that we beat her on an earlier run because she fluffed off the line, we don't need to dwell upon.)
The fact remains that the 300SEL 6.3 is a car in which you can also go to the drags without disgracing yourself.
Another capability of the 6.3 that must go unappreciated in too much of the country is the high-speed cruising ability. We took it across the desert to Nevada to do the top speed runs and found it thoroughly enjoyable and completely comfortable to cruise at 100, 1l0, even 120. At these speeds it was completely sure-footed, showing no tendency to wander, lift, or do anything the least bit unsettling. There was a whisper of wind noise around the front of the front door but other than that there was no real sensation of speed.
In our top speed runs we averaged 131 mph over the 2-way measured mile. The engine was turning 5200 rpm at this speed, which is well over the 4l00-rpm power peak, and this indicates that the car would achieve a higher top speed with a taller final drive ratio. The factory claims a top speed in excess of 140 mph with this same 2.85:1 rear end ratio but we sincerely doubt this. The power (and torque) drop off perceptibly as the engine speed goes beyond the 4100-rpm power peak and our car showed not the slightest inclination toward wanting to run at the 5400 rpm that would be required to attain l40 mph. The whole discussion is academic, of course, as no one has a "practical" reason for wanting to go 140 mph but we are a little surprised at Mercedes-Benz for making such a claim.
In spite of all the praise we've heaped on it, the 6.3 isn't the ultimate sedan. There are lapses from perfection in several areas, lapses that make you wonder. There's a bad driveline shudder as the car is accelerated from low speeds, and we greatly missed having an inside adjuster for the outside rearview mirror in a car that usually is driven with the windows up. It's curious, too. that M-B hasn't caught on to the fact that 2-pedal cars are likely to be driven with two feet and that the wide brake pedal is a particularly useful feature in cars with automatic transmissions. Or that power seats are a way of life for most luxury car owners these days. The seat belts are messy and awkward, tending to lose themselves under the seat and be hard to get out. Furthermore, there's a lot of piston slap when the engine is first fired up, the horn has an insignificant and ugly bleat, the air conditioner compressor is rough in operation.
It isn't perfect, as we said, and we won't try to tell you that it is. But if you take the three or four candidates in the "best sedan" category, evaluate them in all characteristics, score them 3 for excellent. 2 for good and one for fair, the 6.3 300SEL comes out with an appreciably higher score. Try it for yourself and see if you don't agree.
ROAD & TRACK - November 1968