The Motor Sport Road Test --- BMW 850i

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Heavyweight Cruiser

Launched last summer in LHD, fan-fared to Britons as a £59,500 replacement for the 6-series coupés at the September 1990 Motor Show, the BMW 850i is a 19.5-foot, one and three quarter ton, device. One for transporting two adults and two persons of restricted growth, wrapped in an uneasy cross between padded Jaguar V12 luxury and Porsche 928 potency. A German might see the BMW simply as an alternative to the Mercedes SL line. BMW say of their new progeny, “unlike previous BMW coupés, the 850i will not form the basis of a racing car. The purpose of the 850i is quite clear. It provides the driver with the means to cover the road quickly, quietly and safely, whilst delivering that essential BMW driving ingredient, driving pleasure.”

The company have achieved some of those objectives, but we believe they may have been deceived by the previous boom economy of pre-unification Germany into over estimating the demand for heavyweight coupés. In Britain the BMW 850i is now a Special Order vehicle (like the similarly V12-propelled 750i saloons) whose waiting list has shrunk from the much publicised “almost three years” to “6 months to a year, if you are not fussy about colour.” The list price is now £61,950 plus £450 for delivery charges, but there are low mileage examples on offer for £55,000 to £58,000.

What do BMW provide in this spiritual successor to some of the world’s best loved coupés? The essential, and creditable, difference between the 850i and its emotive predecessors of proven motorsports efficiency, is that the 850i is not based on the floorpan of a BMW saloon. This vital difference meant that the engineers felt free to try some solutions on rear suspension that were out of the question for larger production volumes, and were also emboldened to follow Chevrolet Corvette along the production six-speed gearbox route.

Rumour had it that BMW would premiere the 850i with a 48-valve version of their 5-litre V12, but the engine is substantially that of the 750i, anything more exotic reserved for McLaren via BMW Motorsport.

The BMW V12 of today has 300 catalytic convertor-cleansed horsepower; the manual transmission option hauls its 73 inch girth from rest to 60 mph in under seven seconds. From 60 to 130 mph there seems little difference in travelling strain inflicted upon the occupants, who can spend all day and night traversing Europe amidst a lengthy list of standard creature comforts, so long as they can keep up with the 16 mpg appetite for cheaper unleaded fuel grades.

Technical Analysis

The unique bodywork decision meant that BMW also had considerable aerodynamic freedom and that its considerable length (on a comfortable wheelbase of almost 106 inches) was put to work to provide the slippiest production outline BMW have offered. The 0.29Cd figure is a considerable achievement when you recall the width of wheels and tyres that BMW were forced to package under a near 4000 lb vehicle, capable of 186 mph, had the company not adopted their usual politician-pleasing electronic speed restrictor.

Body strength in respect of “static, dynamic flexural and torsional rigidity” is dramatically enhanced when compared with the old 6-series. BMW quote a gain of 30 per cent in this department, despite the absence of a central (B) pillar. The bonus is attributed to basic computer-aided body construction analysis (leading to substantially beefier joints and deployment of many “extra large supports”) and the bonding of both front and rear screens.

You can quarrel with the amount of space provided for people, versus road space occupied by this heavyweight European echo of an earlier Gran Turismo era. Yet the detail engineering is thorough, although one could aspire to a kerb weight saving of more than the present 85 lbs versus the revised Jaguar XJ-S V12, a machine encumbered with its now elderly (but nonetheless silently effective) V12 of aeronautical Merlin proportions.

The V12 is equipped with an electronic power reduction system (ACS) which is activated by hard cornering and relayed symptoms of wheel spin, but this can be locked out by a cabin button. The only modification required to adapt from 750 to an 850i home were “changes to the throttle housing and rerouting the fuel lines.”

One technical highlight that we have experienced in several German examples of the breed, but not in Britain, was the 6-speed gearbox. It has similar gearing to the 31.8 mph per 1000 rpm of our ZF automatic test car. Since the character of the 850i is not overtly sporting, and the manual change is heavily accurate, rather than a flyweight pleasure, this is one case where we would opt for automatic transmission in British use, a remark that would also apply to the Porsche 928 in all but its higher powered forms.

The rear suspension is massively complex with its independent action governed (on each side) by three wishbones, one longitudinal control link and a fifth control (“integral”) link that is attached to the top wishbone and the longitudinal arm. Soft and hard rubber mounts are strategically disposed to assist the BMW handling philosophy: “you name a direction in which an incoming suspension load will arrive; we at BMW have tried to counter it.”

BMW also mount the coil spring and damper separately and provide a very light anti-roll bar. The front suspension is a strut adaptation from the 750i and recent BMW practice, but the track is stretched 24mm/ 0.95 inch over that of a 7-series. It is worth noting that the test car was supplied with the no cost option of Sport Suspension, but since the factory listed four optional settings at the launch everyone we have talked to seems confused as to what is precisely involved. There was a vague “well it uses M Technic (that was separately assigned at the launch) and rides a bit lower.. . .” disinformation, but we cannot be more helpful than that.

The steering characteristics pass through another Bosch microcomputer to produce the eerie numbness already inflicted on 5 and 7-series under the branding Servotronic. The brakes are the biggest we can recall in a series production car, 12.75 inches. BMW boast, “in comparison to the 635 CSi, the brake lining area, the brake disk (sic) area and the wear volume have been increased by 100 per cent.” They are good, but such statements do make you wonder how they thought the old 6-series was ever going to halt?

Cabin

There are plenty of clever engineering touches to the somewhat claustrophobic cabin as well. The feature that could well save your life is the integrated seat design; BMW engineering chief Dr Wolfgang Reitzle assuring us at the 1990 launch that, “it will resist forces up to 2.5 tons.” The integrated reference meaning that all seat belts mountings have been included, so that geometries and mounting points are as near perfect as BMW could create. Even in 1990 the cost was put at the equivalent of more than £1000 per seat, if development engineering time was accounted. . . .

On an everyday basis the standard leather trim and multiple direction adjustment via softly whirring electric motors is the more likely seating memory. You face the legendary BMW whirling propellor symbol with the safety-orientated steering wheel and gaze ahead at a new set of BMW instruments, occasionally distracted by strong windscreen reflections from the sombre interior.

The black and white analogue dial theme remains, but the usual larger dials for engine rpm (5800 is the redline of a 7000 rpm display) and speed (up to 180 mph) predominate. They are flanked by smaller fuel and temperature indications, but the complete display, like some of the lighter grey plastic trims used in this vehicle and the new 3-series, have a faintly cheap Japanese taint. Couple in the flip-up headlamps, à la Toyota Supra and you begin to wonder if BMW designers had any conception of the commercial value of BMW heritage? Or what could happen to values if that aura of overall quality that BMW have managed to maintain (despite some rocky individual failings) were challenged as actually inferior to the oriental products of the Nineties. Unlikely? I would pick the fit and finish of the German launch stock Honda NSX — even though Honda UK will not lend us one until all the media pack have all had a chance of writing it off — over that of 850i. . . .

Our calypso red demonstrator carried silver grey leather well and had a long list of standard features that we utilised regularly. These comprised: air conditioning; central locking; key torch; the traditionally outstanding tool kit; cruise control; the most accurate computer we have used (particularly in respect of cross-checked fuel consumption) and a compact disc player to complement the usual stereo radio installation. I did not set the seat position memories, but found the automatic electrical movement of the wheel to its highest adjustment position mildly disconcerting. Unlike any previous BMW that I can readily recall, the steering adjusts both vertically and longitudinally.

As you would expect in a vehicle that is significantly greedier of road space than its predecessor, front seat occupants do gain on usable space. The pity is that the old element of a usable 4-seater coupé, evident in a number of models back through the 6-series, to the genuinely classic CS derivatives, has been lost. The rear seats are not worthy of the bulk of the vehicle, a cramped joke in poor taste.

At The Wheel

The aluminium V12 ranks alongside those electric seat motors in the lack of commotion created when cranking to life. Thereafter the 60-degree unit wafts the 850 around at 1200 to 3000 rpm with rustling ease and, initially, seems as though it could be a match in civilisation for the Jaguar unit. Press harder, into the three to four thousand rpm band, and the squared-off exhausts emit a much deeper note, one that could not be mistaken for a more urbane Jaguar harmony. Pressed to the lowish 5800 rpm limit, the unit does not feel part of any svelte 12 cylinder legend, but speaks with growling menace of the power it could have produced had BMW Motorsport been allowed to go ahead with the once-planned M-version.

By the standards of the luxury performance category, the 850i has adequate, rather than inspired, performance. By coincidence the automatic 850 performance proved very similar to that of the manual transmission 220 bhp Audi S2 Coupé tested recently, 5-litres establishing an advantage over a turbocharged 2.2 only at speeds beyond the British speed limit. Both shared maximums in the 155 mph band and reached 100 mph from a standing start in comfortably less than 20 seconds. Since the Audi is less than half the price of the BMW, it is obvious that BMW are not particularly interested in ultimate performance from this variant, directing the customer toward the M5 if a large and fast car is required.

Where the 850i excels is as a motorised transcontinental express. At an indicated 100 mph and 3000 rpm, it is almost literally ambling along. The standards of silence achieved between this point and a sustained 120 mph are remarkable, especially in the absence of a central pillar to pin panes of glass more securely.

Assisting strongly in this effortless progress are an automatic gear change that has almost electrical speed and smoothness in its shift qualities and superb ride comfort. This seems to apply virtually whatever suspension coding is supplied to hold up that elongated wheelbase, so we would advise potential customers amongst our readership to at least try the sportiest settings offered, for they do much to cut the front end float that is otherwise apparent on both motorways and country roads. Our only proviso is that the town ride suffers to the point at which thumps over town bumps are perceptible and might be unacceptable to those used to Jaguar suspension standards: the compensation is more driving pleasure in the country than you can obtain with any Jaguar that is not equipped with a Sport pack.

Once the Jaguar is so equipped, whether by TWR-JaguarSport or the factory, the M Technic/Sport BMW has very similar ride characteristics. The other BMW alternative is Electronic Damper Control (EDC, as developed in association with Boge dampers), but I believe this £1000-plus option with its fast-acting choice of triple settings is not the overall answer. You are better off with a properly chosen fixed setting in the first place, particularly on such an absorbent wheelbase length.

The only major black mark awarded against the BMW for its long distance capabilities was the crosswind stability. We had to run at maximum speed around the Millbrook bowl in a 12 mph crosswind and the car was quite a handful (a bit like a bigger version of the Porsche 911), confirming my autobahn experience of the 850 at speeds between 90-130 mph. The large brakes are a match for such speed and weight. The standard four channel antilock braking system operated only at sensibly high pedal loads, even over slippery surfaces.

I never grew brave (foolish?) enough to broadside the big BMW on anything other than a wide test track. If the ASC electronic power-control device is activated it is unlikely that the BMW will do anything other than hint at the fabled tail out stance of yore. If you dispense with ASC, wheelspin is more of a problem than power oversteer in public road employment. Thus, the basic handling trait is one of good natured neutrality to understeer in all but extreme circumstances. Then the dead, but accurate, Servotronic will twiddle Bavaria’s flagship into orderly conduct with commendably small angles of body lean.

Verdict

Motor Sport was pretty hard on the 850i on the occasion of its German launch and I cannot say that I wanted to upset old UK BMW friendships by repeating the dose: I therefore did my best to ensure that AN Other was assigned to the British evaluation. That manoeuvre failed, but we did get three other people to drive our 850i and searched their notes for a warmer tone to the piece. Perhaps because the test was largely conducted in the grip of winter I failed to find such overall contradiction of our initial view. It is worth stating, however, that the 850i is one of the very few current cars we can recall that actually deserves the now-debased appellation Gran Turismo, for that is exactly the role it can ably fulfil. The initial BMW (GB) waiting list has withered away, mostly because of the recession rather than any public perception of shortcomings in the 850i. Yet I stick to our view that the 850i was a golden opportunity for BMW to offer another agile and adaptable coupé, rather than a conspicuous testament to the “bigger is better” philosophy.

Consistently denied at BMW are rumours that a V8-engined lower cost alternative 8-series may answer such criticisms, but BMW themselves seem to be following the route of supplying a wider range of coupés in each model line. This process begins with the two door 3-series (probably badged as the 4-series and likely to restore an M3 to the line) this autumn. — JW

***

MOTOR SPORT TEST RESULTS: BMW 850i

SPECIFICATION:

ENGINE: Water-cooled, light alloy head, 60 degree V12 and SOHC cylinder heads of 12 valves apiece. Capacity 4988cc (84 x 75mm), Bosch Digital Motor electronic ignition and fuel management with over-run fuel cut-off and fault memory diagnosis; 8.8:1 cr; catalytic converters. Max power: 300 bhp @ 5200 rpm. Peak torque: 331 lb ft @ 4100 rpm.

TRANSMISSION: Front engine, rear drive via 6-speed manual or (as tested) 4-speed ZF automatic with Sport and Economy modes.

GEAR RATIOS: First: 2.48; Second: 1.48; Third: 1.00; Fourth: 0.73 … 31.8 mph per 1000 rpm; Final drive: 3.15.

BODY: Steel monocoque 2-door 2+2 Coupé; Petrol tank of 90 litres/19.8 gallons. Drag coefficient 0.29Cd.

DIMENSIONS: Wheelbase 105.7in/2684mm; front track 61.2in/1554mm; rear track 61.5in/1562mm; width 73.0in/1855mm; length 188.2in/4780mm; height 52.8in/1340mm. Kerb weight 3938lb/1790kg.

FRONT SUSPENSION: (No cost Sport option) MacPherson struts, lower arms, hydraulic dampers, anti-roll bar. Steering, Ball and nut, hydraulic power-assisted Bosch Servotronic, ratio 15.4:1

REAR SUSPENSION: Independent action, 5-links, damper struts aft of coil springs, hydraulic damping, lower wishbones and anti-roll bar.

BRAKES, WHEELS, TYRES: Power-assisted, vented 12.75in/324mm diameter front discs; solid rears also of 12.75in diameter. Bosch ABS electronic anti-lock braking. Light alloy 7.5J x 16 inch wheels; Uniroyal Rallye 440 of 235/50 ZR 16.

PRICE: £51,950, UK taxes paid.

MANUFACTURER / IMPORTER: BMW (GB) Ltd. Ellesfield Avenue, Bracknell, Berks. RG12 4Ta

CLAIMED PERFORMANCE: Max. speed 155 mph; 0-60 mph 7.4s (auto)

TEST RESULTS: Test conducted at Millbrook Proving Ground using 1991 Correvit electronic measuring gear. Weather conditions: Dry tarmac.

ACCELERATION: 0-30 mph 2.8 (3.0) seconds; 0-40 mph 4.0 seconds; 0-50 mph 5.4 seconds; 0-60 mph 7.2 (7.6) seconds; 0-70 mph 9.2 seconds; 0-80 mph 11.3 seconds; 0-90 mph 14.5 seconds; 0-100 mph 18.0 (19.5) seconds; 0-110 mph 23.1 seconds.

Sport automatic gear change proved fastest, manually shifted comparisons are given in brackets at key points.

FLEXIBILITY: Third gear 50-70 mph 7.01 seconds; Fourth gear 50-70 mph 7.11 seconds.

Standing 0.25 mile/400 metres: 15.52 seconds @ 94.1 mph

Maximum speed, 2.2029 bowl: 156.01 mph

Maximum gear speeds at 5000 rpm: First 49.9 mph; Second 83.8 mph; Third 130.5 mph

Overall fuel consumption: Test Average 16.7 mpg, Best 17.0 mpg, Worst 8.4 mpg.

Government mpg figures: Urban 14.3 mpg; 75 mph 27.4 mpg; 56 mph 32.8 mpg.