Perfection looms

When Mercedes-Benz and Porsche mesh brains to create a sports saloon, you expect a memorable motor car: in the 500E you obtain as near to class perfection as we can expect in the early ’90s. The pity of it all is that few of you will share my enthusiasm for this suave purveyor of tremendous speed and uncommon luxury, as it is available only in lefthand drive. And the price is an unreasonable £57,200. Even then leather upholstery is a £1728.81 option.

The insertion of larger engines into smaller saloons is a proven performance formula that often allows the resulting vehicle an air of relaxed speed that is unattainable via modifications to the existing motor. Mercedes also practises the art with a softer blend between its 4.2-litre V8 and the mid-range body, but this 400E has yet to arrive in the UK. Engine transplants are often associated with BMW in this sector of the market, Alpina making such a profitable living from oversize editions of the 3- and 5-series that the factory was forced to follow suit on a number of occasions. The best known example was the M5 blend of 5-series body and 3.5-litre six, but these days the M5 (listed at £46,850) has its own 24-valve in-line six, which the factory announced in January would go from 3.5 litres/315 bhp to 3.8 and 340, accompanied by 294 lb ft of torque. This is the competitor that was targeted for the 500E, but it would not surprise us if BMW imitated the opposition in future and fitted its new V8 in the M5.

In essence the 500E mates Mercedes’s midrange body and its five-litre, 32-valve V8. This civilised cocktail would provide well over 160 mph, were it not for the usual (155 mph) electronic limiter. Despite a four-speed automatic transmission as standard equipment, the 500E flits from rest 60 mph in just six seconds. Yet its true ability lies in oozing from 60 mph ever so swiftly, seductively stabilising at any cruising speed you dare to achieve between 70-140 mph.

Detail development, endurance runs and assembly was, and is, the responsibility of Porsche at Weissach and Zuffenhausen, where a maximum of 12 units per day are produced. External signs of the 326 bhp power transplant are modest, although the steel wheel arches are notably extended. There is not a rear spoiler in sight and the aerodynamic drag coefficient remains an excellent 0.31 Cd.

A unique set of 8Jx16 alloy wheels carried D40 Dunlop 225/55 covers on the test car. The hard high speed (ZR rated) Dunlops detest ice, which led to some very entertaining winter antics in a vehicle with 50/50 weight distribution, masses of torque (353 lb ft at 3900 rpm) and rear drive. However, it did stay upright on one particularly exposed and icy motorway tributary that deceived and inverted a conventional RHD 190E coming the opposite way. . . This was possibly due to the replacement components wrapped around the Bosch LH-Jetronic injection system, which talks to the Automatic Skid Control (ASR is the German abbreviation) via an external link. We would have preferred a conventional limited slip differential, but there is no doubting the delicacy that the electronic nanny allows you to exercise in temperatures as low as minus seven degrees.

Compared to the 300E on which it is based, a 500E has 37 mm of additional front track, a 38 mm stretch aft and a stance 32 mm lower, all upon stiffer yet still supple suspension. Ride quality is toward the Porsche sports end of the spectrum at town speeds, but smoothes out to reach high standards of absorption beyond 35 mph.

The independent layout retains Mercedes’s effective multi-link rear and strut with divorced front coil spring, but has been substantially strengthened, a process that has been extended to the recirculating ball power steering linkages and transmission components.

The brakes are generously proportioned and come complete with four-piston calipers for the front and a standard ABS monitor. Yet they remain the weakest point in the car, faced with restraining 3740 lb/1700 kg.

At nearly £60,000 for a four-door saloon you would hope that the standard equipment list was extensive. Our pearl grey demonstrator with hectares of (optional) black leather complied with that expectation. Air conditioning, Becker Mexico radio/cassette, the most sensitive cruise control we have encountered, walnut trim and electrical assistance for a long list of creature comforts should satisfy most sybaritic tastes.

The cabin was laid out with typical Mercedes fit and finish, which means that the walnut may look out of place and the 15.4 in diameter steering wheel is more suited to a racing truck. However, everything is where you want it and the complete effect is as though this hybrid was hewn from padded granite.

In action the lively feedback of the steering was the first surprise, for it relays messages of chunky Dunlops at skittish play over adverse cambers and tiresome bumps, but these are never allowed to upset the 500E’s poise. Driving becomes a dialogue between driver and car, where so many large saloons have a numbing effect on this exchange. The company attributes some of this transformation to “a narrow, flexible, anti-roll bar” which is apparently mounted with exceptional rigidity to allow “a sensitive feel and balance to the car”. It’s not often you find PR words so accurate, but that is just how the 500E felt to us.

Travelling at simply astonishing speeds, the Mercedes maintains its dignified silence within. The 32-valve V8 is rarely extended to the 6000 rpm redline. When you do work the V8, the world zooms by, leaving you to wonder at the strength of the subdued forces at work on your behalf.

I herald this amalgamation of Porsche verve and Mercedes quality as the supreme sports saloon sold in 1992. The 500E is restful when you want relaxed progress, stunning when speed tops the list of priorities.