June 1968


Mercedes 300 SEL 6.3 V-8

How does it feel to drive a luxury sedan that performs on par with some of the world's finest GTs?

Bernard Cahier

Mercedes engineers, because of the racing background of the company, are mostly sports minded, with sharp new ideas for their work. And yet Mercedes has failed to show us an exciting new high-performance car since the days of the forward-looking and very fast 300 SL. Mercedes' high-finance-type management is obviously more interested in the making of mass-production cars rather than a limited series of glamorous fast sports cars, and this in spite of the fact that the Mercedes image was built upon their racing successes.

In any case - and fortunately for those who like unusual "rubber burning cars" with that very certain "go" - the Mercedes management, encouraged by their sales, has decided to reward their good, faithful engineers by letting them build something with a little love besides scientific accuracy.

The recette de cuisine is quite simple if you have the right ingredients: you take a long wheelbase Mercedes 250, throw away the 2.5-liter 6-cylinder engine, replace it with a meaty 6.3-liter twin-cam V-8 with fuel injection, reinforce the chassis, add bigger ventilated disc brakes and wider wheels with high-speed tires. This gives you your plat de resistance, the 300 SEL 6.3-liter a designation typical of unimaginative German automobile naming.

The result of the entertaining engineering exercise is quite spectacular. Here is a compact sedan, 196 inches long, which with 300 hp under its hood - is capable of competing in both handling and performance with most of the world's famous high-performance cars.

The price tag is not cheap - $10,000 picked up at the factory - but the car is spectacular, comfortable and immensely satisfying to drive.

I had one of the very first 6.3-liter cars on test and I came back highly enthusiastic. Frankly I could not really find very much wrong with this new German "Hot Frankfurter," except, of course, its price tag and its conservative appearance which is not even dressed up by some of those beautiful magnesium wheels now available. The interior, too, is dull, and I believe that Mercedes could have easily found a "juste milieu" in this field which could please both the conservatives and the liberals (but earlier there was mention about the people who named this car the "300 SEL 6.3-liter").

What surprises you immediately when you drive the 6.3-liter is the large amount of comfort - around you, under you and everywhere. Second and here you must beware - you do not realize while driving that you are actually going fast, very fast indeed! Naturally you very quickly become accustomed to that unusual combination of speed, fierce acceleration, quietness and comfort. However, at first you have a tendency to go quicker than you think, that is until that first nasty curve comes at you like a wall!

The ohc V-8 engine is a beautiful unit, with a remarkable torque figure of 434 lbs.-ft. at 3000 rpm. The block is made of iron, but the head is in aluminum. Direct Bosch fuel injection with 8 plungers is used. Mercedes gives a 300-hp SAE figure at 4100 rpm which is modest by American standards. Yet the new Mercedes - which is no light baby with a curb weight of 3835 pounds is capable of out-accelerating the majority of American sedans claiming 100 hp more! (This does not refer to handling because the new Mercedes obviously handles far better than any American car as well as out-brake them time after time.)

With three people aboard and the automatic in position No. 4 (that's right- four), I recorded the following speed and acceleration figures which speak for themselves:

0 to 50 mph in 5.1 seconds
0 to 60 mph in 7 seconds
0 to 70 mph in 10 seconds
0 to 80 mph in 12.1 seconds
0 to 100 mph in 17.8 seconds
TOP SPEED: 136 mph

The quarter-mile figure was not recorded but should be around 15-1/2 seconds. For comparison the 911S Porsche, the Iso Rivolta Chevrolet and the Ferrari 330 GTC do 0 to 60 respectively in 7.6, 7.7 and 7 seconds.

All this speed and acceleration are not felt in the 6.3, and at all times you think you are going at a leisurely pace except that you are sometimes cruising along at 120 mph with all the speed, comfort and silence that many cars do not have at 70 mph.

As said earlier, the interior of the 6.3 is dull - truly a misfortune because the minute you drive that great car you wish you had something better to look at, inside and out. But then there is another point of view: this conservative looking car will please a certain kind of person from the serious type to the sporty type, who, for the fun of it, is going to remove the "6.3-liter" insignia from the trunk just to infuriate Porsche or Ferrari drivers who think they are actually competing with a 300 SEL with a modest 180 hp.

The driving position and seats are great, and the general finish of the car is superb. The one I drove had an optional air conditioning unit and the electric windows which are standard equipment. The power steering and the brakes were the best I have ever experienced on a sedan. The very quick-action 4-speed automatic gearbox (standard equipment) which is operated by a well located floor type shift was also of the highest standard for operating ease and comfort.

The suspension, while being set for this 136 mph car, is similar to that of the 300 SEL - meaning it is independent in front with swing type axles at the rear. This suspension is completed by rubber air cushions and a self-leveling unit to keep the car in the same horizontal position regardless of load. A very forgiving car on open roads, the swing type rear axle does not appreciate too many mountainous, tight, curved roads where hard braking causes the rear wheels to dig in. Still, the 6.3-liter is a magnificent machine to drive. With it you find as much pleasure as you do driving a big sports car, differing only in that you are truly comfortable and you can converse with your companions (note plural).

The 6.3 understeers, which is normal for a car with an engine weighing over 700 pounds up front, but at no time does this understeer become alarming, and that quick, smooth-as-silk, 2-1/2 turn steering really does the job for any correction.

I consider the 6.3-liter Mercedes to be the safest, fastest and most comfortable 4-door sedan made today, considering the fantastic speeds you can achieve in full safety and relaxation. /MT

MOTOR TREND/JUNE 1968