BMW 3.0S Sedan

BMW 3.0S

In a year dominated by the launch of the wonderful HQ Holden, our Bavarian friends launched what was, at the time, almost unquestionably the greatest 4 door sedan the world had ever known.  The 3.OS was a development of the 2800 sedan which it replaced in Australia. The cheaper and less powerful 2500 was continued and incorporated the minor styling and trim changes made on the 3.OS.

The Silky Smooth 3.0 Litre Straight Six

BMW first went to a 3-litre engine in the CS Coupe but inevitably the big sedan was destined to get the extra capacity. The increase was achieved by boring out the engine from 86 to 89 mm, this took it from 2788 to 2985 cc. Power went from 192 (SAE) bhp at 6000 rpm to 200 bhp and torque from 173.6 ft/lb at 3700 rpm to 188 ft/lb. That didn’t sound like much of an improvement even by the standards of the early 1970s, but BMW owners know that Bavarian horses are more genuine than most and small incremental increases did add up to a much bigger difference on the road.

To back this up there were new ventilated, four-wheel disc brakes and power steering and a heated rear window were now standard along with headrests for all four seats. The six cylinder models - both 3.OS and 2500 - were surprisingly easy to recognise. Extra bright metal around the windscreen and on the body, vertical extractor vents on the C-pillar and, on the 3.OS, a matt black grille and headlight surrounds gave both a longer, lower look and managed to make them seem more expensive and more tasteful at the same time. Inside there was much greater use of the traditional "real" tree wood. It was on the doors, gear knob, dashboard and steering wheel.

BMW engineers softened the suspension to quieten the ride – which was already pretty damn quiet. All these changes were discreet rather than revolutionary but they nevertheless took the 3.OS to an undisputed lead in the top sedan stakes. The 3.OS had slightly lower second and third gear ratios than the manual box fitted to the 2800 and the engine featured an ignition cut-out which restricted revs to 6200 rpm although some owners claimed it to be a little higher than that in reality. The improved performance wasn't really noticeable down low, although there was more torque, but in the upper reaches the 3.OS would surge forward in a manner which made a mockery of the relatively small 3-litre capacity. A sports car from the early 1970s wouldn't be disgraced with a standing quarter mile time of 16.2 seconds and the ability to reach 60 in under nine seconds and the ton in under 24 seconds.

Away from rest the BMW would squat its tail on the road, spin its wheels for the first few yards and then it was pure forward movement with the driver slicing the gear-lever through its positive gate as fast as their hand could move and without the synchromesh baulking or being beaten. The ratios were perfectly matched for the engine's power characteristics with first running to 35 mph at the redline of 6200 and second 60 mph and third 94 mph. There was sufficient torque down low to allow the car to pull away from even 20 mph in top gear - it would go lower but transmission snatch discouraged the practice - but the manual gearbox encouraged far more gear-changes than were necessary.

At the top end the 3.OS reached 5700 rpm which was close enough to 125 mph and such were the in-built reserves of roadholding, braking, engine power and quietness the Beemer had have no trouble maintaining two miles a minute – however there were few Australian roads then and now that were good enough. The 3 litre engine seemed quieter high in the rev range compared to the 2800 but in every other respect it is indistinguishable - totally without temperament, supremely smooth right through from idle to the redline and still surprisingly economical considering the performance.

On The Road

Owners and road testers were reporting figures around 20 mpg in a mix of country and city driving, and with some serious flogging that figure would only rise to around 22 mpg. Even so, with a petrol tank of 16.5 gallons including a reserve of 1.65 gallons, this gave a touring range of just over 200 which was hardly sufficient in the BMW which was capable of putting away so many miles into each hour. Like all great cars the BMW flattered the driver with a balanced, incredibly stable feeling that came from magnificent brakes and incredible roadholding ability.

Making An Average Driver Look Good

Just like the BMW 2800, the 3.OS reinforced the feeling that this car combined the taut, precise feel of a solid sedan with the manoeuvrability and almost the agility of the then-best small sports cars. Of course it wasn't as quick around corners as a Lotus Elan but no other sedan of its ilk could be driven around corners as fast. Away from the long straights, which it covered in great strides, the 3.OS enjoyed tackling a twisty section, certainly any driver who claimed to love motoring would have got hours of pleasure driving the BMW. On normal or rough roads it was very predictable it just went around corners. Nothing more, nothing less. It just went around. It made an average driver look very good.

There was mild understeer to make the car inherently stable and it was only when the car was approaching its astonishingly high limits, and when the driver was trying very hard, that the understeer turned to a delightfully controllable oversteer under power. Lifting the throttle had the same effect - the tail moved out but a touch of correction and the car maintained the desired line. All this happened at speeds far beyond what you could expect from a five-seater luxury sedan. And when using all the available acceleration up through the gears it emitted a marvellous exhaust note that seemed to say efficiency – it is a chorus that BMW aficionados have come to enjoy over the following decades. At the same time when cruising ton-up with all the windows closed it left the engine noise behind and settled down to a quiet hum.

Road Safety 1970s Style

When driving fast there was always the knowledge that the huge vented discs were just a few pounds pressure away. Fade was almost non-existent and could not be induced even if you tried repeated hard stops from high speeds. The reassuring feel they provided was what true safety, 1970s style, was all about. They never locked up a wheel and stopping distances were almost absurdly short. The power steering was light but retained some resistance and feel. It was low geared and this was accentuated by the huge steering wheel (something common to German cars from this period) but the turning circle was very tight at only 32 feet and for most practical purposes the wheel required only small movements.

oftening the suspension improved the ride although body roll was increased slightly and the driver had an initial impression that the car tended to wallow around corners and at high speed. However this was an impression only, and the truth was that the Beemer afforded utterly brilliant handling and roadholding. That ride carried through to the seats which had been reshaped for greater thigh support. They were very comfortable and offered greater lateral support with curved edges on the squabs. There was generous adjustment fore and aft and the headrests were sensibly shaped and could be used for additional support on a long trip. The rear seats were just as comfortable with lots of leg and knee room and there was sufficient width for three adults.

Visibility through the large glass areas was outstanding and together with the light steering made parking easy. However the bonnet was so short it didnt have the ego boosting expanses of sheet metal which did so much for the driving appeal of a Mercedes-Benz. That was essentially the difference between the two. The Mercedes was a marvellous, prestige touring car for middle-aged gentlemen, the BMW was at least as comfortable and luxurious but it was for driving enthusiasts less concerned with badge kudos.

he layout and design of the interior confirmed this sporty image. The big steering wheel had a wood rim and the superbly lit instruments - limited to a speedometer, tacho and petrol and water temperature gauges - were white on black for easy read-out. All other information was provided by a row of multi-coloured warning lights. Two steering column stalks controlled the wipers and washers and the turn indicators and headlight flasher. The other minor controls were within easy reach on the dashboard.

he pedals were angled to the right to provide more room for the driver's left leg but even so their feet could become caught under the clutch pedal. Another complaint from some test drivers and owners alike was the angle of the accelerator pedal being too vertical, something that really only became bothersome on long trips. Not so much when the pedal was further depressed for when you were doing autobahn speeds, but here on crappy Australian roads with restrictive top speeds it did become an issue.

The heating was excellent for front seat passengers, not so good for those in the rear and ventilation wasn't quite adequate for Aussie summers. The finish was, as you would expect from BMW, outstanding, and befitted a car with a A$10,000 price tag – and that price did not include the Golde sunroof, which was an extra cost option. The problem with early models fitted with the sunroof was that it lacked a wind deflector on the forward edge and caused the body to develop unbearable drumming at anything above 40 mph. BMW wisely added a deflector on the later models.