Sweet Dreams

Sweet Dreams

SHOULD you be a captain of industry, a chauffeur or just a plain day dreamer, this is a road test that should appeal to you. If, however, you are a car enthusiast who is never likely to own or drive the cars that feature in the road tests you read, don’t despair. At first sight, the BMW 750i seems a dull beast, a bigger engined version of the equally dull 735i, but in fact the Bavarian manufacturer is putting it on a pedestal claiming that it can be considered as the world’s best car.

Let’s cast aside the special interests of the chauffeur and those of the company executive and examine the car for what it is.

First place to investigate is under the bonnet where we discover BMW’s 4988cc V12 engine. This 6-degree all-alloy V12 is the same unit that was first seen in the 750iL which was introduced to Britain a couple of years ago thereby spoiling Jaguar’s claim of having the only V12 as a flagship model.

Compared to the Coventry manufacturer’s masterful engine, the German engine is lighter, 529Ibs to that of the Jaguar’s 7421bs, is more powerful, developing 300 bhp compared to 295 bhp and has greater torque, 317 lb ft against the Jaguar’s 332 lb ft. And yet, despite all its marvellous attributes, it somehow remains unremarkable. Before influencing your opinion any

further, let’s look at the engine as a piece of engineering. Designed from the start to use a catalyst, the power is neither enhanced nor reduced whether fitted or not. The reader should also be disabused of the notion that the V12 is nothing more than two six-cylinder engines mated together for even though the bore and stroke of the V12 and the 2 4-litre are the same, the 5.0-litre is all-new.

The high silicon content in the block has meant that the cylinder walls could be etched with Nikasil, the advantage being that the exposed silicon crystal cause a clear reduction of friction and also wear.

By its very nature, a V12 is smooth, and the BMW unit is exceptionally so. Even up to 3000 rpm from tickover, there is hardly a tremour, the dozen counterweights in the seven main bearing crank effectively doing their job. It is a tribute to the German engineers that their powerful 5.0litre masterpiece should be as docile on crowded urban roads as any other less complicated engine. Bosch electronics play a significant role in the car. A third generation system combines the operation of the injection and

ignition components, while the throttle is electronically controlled enabling the engineers to stop the car exceeding 155 mph. The same system also enables the car to be fitted with an Automatic Stability Control system which uses the ABS antilock brake sensors to detect when one of the driven wheels is about to lose traction and spin. It automatically cuts the revs, even if the accelerator is pressed hard to the floor, until maximum grip is obtained in both wheels. Without doubt, it has to be one of the best assets of the car. With the operation switched on, it is impossible to make the car oversteer or behave in an unseemly fashion. If you want to, you can turn it off to have a bit of fun, but that really is defeating the purpose. It is similar in principle to that developed by Saab as described in the March ’89 issue of MOTOR SPORT and to Mercedes’ ASD function.

From the driver’s point of view, there is enough on-board technology to keep you amused for hours. Not only are the door mirrors heated, for instance, but they automatically swivel down to view the side of the car when reverse gear is selected.

The driver’s mirror in the cabin has a built-in eye which causes it to dip automatically if the light behind is too bright. A switch on the mirror varies this sensitivity. The intermittent action of the wipers can be programmed by the driver to a maxi

mum of 20 seconds between each wipe. Even with the wipers fully on, they will revert to intermittent mode when the car is standing still, at traffic lights for instance. Not only is the windscreen around the wiper blades automatically heated when the ignition is switched on, but so are the windscreen washer jets.

Green light-emitting diodes (LEDs) indicate the interval until the next service, the fewer that are on when the ignition is switched on, the sooner the next service is due. A yellow LED indicates that the car is in immediate need of a service and the red LED means that a service is overdue. The small clock symbol in conjunction with the inspection display informs the driver that an annual inspection is due. All these displays are extinguished as soon as the engine is started and are re-set at the service after the appropriate work has been performed.

The driver is constantly informed by a control panel about the state of the car. When the Automatic Stability Control is in operation, a message is silently flashed up, but when the brake pressure, brake fluid and the engine oil pressure indicate low levels, a gong sounds and the relevant message is flashed up.

Other messages announced with a gong include the coolant temperature being too high, the handbrake still applied when moving away from rest, a brake light failure and when the car is overloaded (the rear axle load limit has been exceeded) or the self-levelling has a fault.

A priority 2 display indicates when the automatic transmission has a defect in the shift electronics, when the brake linings are worn, there is a system fault with the ASC, when various bulbs and fuses have blown, when a door or boot lid is open, and when a trailer light fuse has blown.

Such is the complexity of the system there is even a lower grade priority for warning the driver that the engine oil has dropped to the minimum, the coolant level, the power-assisted and washer fluids are too low, or even the message Check Control’ which shows that there is an electronics defect within the system itself.

These displays appear primarily at the end of each journey when the ignition has been turned off. Several displays may appear in succession. Even after the ignition key has been removed and the display has gone out, the information can be called up again for another couple of minutes. Another electronic factor is the automatic transmission, which until the arrival of the 850 Coupe is the only choice. Three different modes can be selected, ‘M’ for single-gear driving (third gear if ‘D’ is selected), which is useful for icy roads, towing a trailer up a steep hill etc. The ‘E’ mode is for Economy and the ‘S’ for Sports, the point at which the car elects to change gear dependent on the setting. Jumping from `E’ mode to ‘S’ often provided the kickdown necessary for overtak

ing, an area in which the V12 seemed slightly ill at ease.

As with the transmission, the damper settings are electronically controlled, ‘K’ for ‘comfort’ and ‘S’ for Sports. Unfortunately neither is very satisfactory as the first setting allows the car to wallow just a little bit too much for true passenger comfort, while the Sport setting is too harsh for such an executive saloon. The Jaguar driver would soon feel ill at ease in BMW’s finest, a sensation made worse by the susceptibility of the enormous tyres, 240/50 ZRs on 7.7 inch rims and 16.3 inches in diameter, to travel off-line on poor road surfaces.

The car is adorned with nice touches, such as the hand lamp in the glovebox which is automatically recharged whenever it is returned, the built-in cut-out stopping any damage. For the executive seated in the back, even though the 4.5 inches which differentiate the 7501 from the 750iL have been taken from the area behind the front seats and the rear wheel arch, there is still plenty of room to spread out. The driver and passengers have their own temperature controls for the heating and air conditioning. Although not a feature of the test car, it is possible to obtain a heating system for the car which can be program

med to switch itself on up to half an hour before the start of a journey. There is plenty of storage area including a stowage compartment in the rear centre armrest, and the windows and sunroof can still be closed even when the driver has removed the ignition key from the lock. Above all, whether driver or passenger, it is a comfortable car. Ther large boot is more than capable of carrying three suitcases plus other smaller items.

From the outside the shape is tidy, but unexciting, especially when compared to the new 5 Series BMW and is on a par with the larger Mercedes-Benz. It lacks, however, the poise of a Jaguar. From an engineering point of view, there is no doubt that the whole car is superb from the ergonomics to the build quality. It handles well and although it is

not the type of car that should be driven vigorously along country lanes, it is quite capable of absorbing all sorts of punishment meted out with the proviso that the ride is suspect as mentioned.

The engine is an enigma. It is better than Jaguar’s being smoother, more powerful and refined, and yet, somehow, it lacks the pep of its British rival, especially when overtaking, which is when the various selection modes on the automatic transmission prove so useful. For the chauffeur, I would say definitely yes, for the executive, maybe, but it lacks the authority of a Mercedes, a Daimler or even a Jaguar, and for the enthusiast, definitely no, for all eyes must be on the BMW M5 for that is the car which BMW can genuinely claim is the best all-round car in the world. WPK