Subtitle: Advanced 4wd puts all the power on the pavement - even in performance driving
Photo caption: Alfa Romeo's new Q4 - a 4wd Quadrifoglio - gives wonderful V6 engine sounds and amazingly neutral road-hugging handling in comfy, sporty sedan package

With its seemingly progressive farewell to the U.S. market, Alfa Romeo will not import the Q4, the four-wheel-drive Quadrifoglio. It's a pity because this $40,000 Alfa is the best 164 ever built.

As a four-seater 4wd sport sedan it has no rival in the world, though you can find something below and above it in Audi's line - either the five-cylinder 2.2-liter turbo or the 4.2-liter V8 Quattro S4.

And while both BMW and Mercedes offer all-wheel-drive, their versions are designed more for skiing enthusiasts than sports car enthusiasts. Forget Acura, Lexus or Infiniti: There's no 4wd in these Japanese luxury channels.

So what is this Alfa 164 Q4? It's simply the latest evolution of the 3.0-liter, 24-valve 230 hp V6 Quadrifoglio, fitted with the most sophisticated (and complicated) 4wd system to ever appear on a production road car.

Called Viscomatic, this system was developed by Alfa in conjunction with 4wd specialist Steyr-Puch of Austria. It represents a further development of the experimental ideas introduced on the Proteo coupe. This was a concept car that Alfa developed in total secrecy from its Fiat bosses at corporate headquarters in Turin and unveiled with great fanfare at the 1991 Geneva Motor Show.

A huge amount of work (and money: $34 million) went into the Q4's development, because of its radically innovative design and high level of sophistication compared with similar permanent 4wd systems.

It's interesting how the Viscomatic system splits the torque between the front and rear axles. It uses a variable viscous joint continuously driven by an electronic control unit mated to an epicyclic differential. The control unit tells the viscous coupling to cut in every time the speed difference between the two axles exceeds a "memorized" value. If slip between the two axles is excessive, the differential and viscous coupling reduce the transmitted torque. It does this by decelerating the external casing of the coupling itself.

The amount of drive torque transmitted to the rear axle can be adjusted from zero (making it essentially front-drive) to 100 percent (making it pure rear-drive). Both these extremes occur only when the front or rear wheels lose their grip entirely.

The Viscomatic's electronic control unit communicates instantly with the microprocessors in both the Bosch Motronic engine management system and the ABS. The control unit continually processes information on running conditions, such as the angle and speed of each wheel, the steering angle, brake-pedal pressure and whether or not reverse gear is engaged.

The Q4 4wd system also includes a conventional (free) front differential, and a Torsen differential at the rear. The Torsen splits the torque transmitted to the rear wheels in real time, on the basis of the instantaneous grip of each one.

When traveling at a constant speed on a dry road, the system splits torque in proportion to the load on each axle. In other words, torque is split constantly between the two axles according to total drive torque required, steering angle, instantaneous slip between the two axles and vehicle speed. In the case of light braking, a larger amount of torque is transmitted to the front wheels. While the load is proportionally increased on this axle, the drive to the rear axle remains engaged. This way all four wheels transmit engine braking momentum to the ground, lessening the demand on the braking system.

An interesting feature of the Viscomatic system is the absence of stress on the steering wheel when comering. In fact the system recognizes a cornering maneuver from the steering angle, and adopts a specific drive torque split.

When grip is reduced by slippery roads, the system uses specific computer maps that guarantee constant traction no matter the conditions.

What is the result for the driver of this boatload of technology? For starters, the good power and the massive torque, 206 lb ft at 5000 rpm, of Alfa's melodious V6 are always maximized and transmitted to the road in the most effective way. With no wheelspin, no torque oversteer, the system always delivers an extremely responsive and neutral car. The Q4 truly handles like the proverbial train on rails. And this happens with superb acceleration: from 0 to 100 km/h (62 mph) in just 7.5 seconds. Top speed is electronically limited to 150 mph.

As impressive as those numbers appear, the real excitement comes from the car's ability to go much quicker than you'd expect from a four-door sedan, thanks in no small part to the short-ratio Getrag sixspeed gearbox. The engine's staccato is as stirring as the ride, especially knowing that the technology is enabling you to get virtually everything out of the car. Though it's easy to get lost in the excitement, a glance at the fuel gauge will bring you crashing back to reality. Wringing all you can get out of the Q4 comes at cost of getting just 11.4 mpg. It's a small price to pay the piper for a great dance.

Photo captions, pg. 1: A perfect V6 - three litres, 24 valves, four cams and 230bhp
Pg. 2, top: Four-wheel drive makes the Q4 the best 164 yet. Claimed top speed is 149mph. Interior, left, has improved over the years; leather seats are standard, Recaros an option. Attractive alloy wheels, top left, are shod with 205/55/ZR 16s
Bottom: Alfa's viscomatic four-wheel-drive system was developed in conjunction with Steyr-Daimler-Puch and features variable pressure viscous coupling allied to both an epicyclic and Torsen limited-slip diff. It allows an infinitely variable torque split between front and rear wheels

Alfa's reputation of not being able to build good big cars has finally been laid to rest with the 164 Q4. If Q4 seems an odd sort of label, and it is, there is a reason for it. The Q stands for Quadrifogolio (or four-leaf clover, an Alfa symbol for decades) and the 4 for four-wheel drive.

Idiosyncratic? Of course, but it will be a sad day when we get the mundane and expected from Alfa Romeo. The difference now is that quirks like the Q4 name are charming oddities on top of a thoroughly engineered and developed concept rather than an attempt to build in character to mask a flawed design.

Alfa is now firmly wedded to the four-wheel-drive route; from the less than successful start with the 33 Sportwagon it's developed through into Touring Car Championship winners and finally this, the perfect Alfa Romeo flagship.

To some it was always a shame that the 164 was front-wheel-drive - it just didn't seem right. Fine for the Alfasud it may have been - but not for a large performance saloon. That worry has now gone, as have any doubts about the performance side. The first 164s from 1988 were only adequately quick but the power of the superb V6 has been upped steadily until the Q4 now finds itself with a 3-litre 24-valve quad-cam version producing 230bhp at 6,300rpm. Actually that's no more than the most powerful of the two-wheel-drive versions but it now has one of the flattest of torque curves all the way from 1,000 to 6,000rpm, with a maximum of 206lb ft torque coming in at 5,000rpm.

That power and torque is now fed to all four wheels through a system developed in conjunction with 4WD specialist Styr-Daimler-Puch which can claim to be the most sophisticated 4WD set-up around. It utilises viscous couplings (in which the fluid density can now be varied through a hydraulic pump to alter the slip), an epicyclic differential and a Torsen rear diff. The system is integrated with the ABS and the Motronic engine brain to offer what seems like complete flexibility. The torque split between front and rear wheels is infinitely variable; in extreme conditions all drive can go to either the front or rear wheels and it chooses the appropriate split for all circumstances. Under heavy braking, for example, there's no drive to the rear, allowing the ABS to work, but in normal conditions the brain switches the drive around automatically according to such criteria as vehicle speed, steering angle and whatever slip there is between the front and rear wheels.

To convince the sceptical that a car which looks outwardly unchanged is dramatically different, Alfa chose a demanding test route near Parma which involved moderately steep mountain roads, a few hairpins and an endless succession of bends. That was followed by a session around the short Varano circuit.

It doesn't show from the outside but the changes to accommodate the four-wheel-drive system are many, with redesigned suspension units, repackaged exhaust, and a new gearbox, a close ratio six-speed Getrag unit.

Another thing that distinguishes the 164 from previous Alfas is that it needs no acclimatisation - unless you want to use the heating or ventilation - so the driver is immediately at home. The Getrag gearbox shifts precisely and easily, which is just as well because (that flat torque curve notwithstanding) Alfa expects you to use every gear to the full to get the best out of a wonderfully responsive V6. If it has a weak spot it's in the torque; it may sound churlish to speak of a lack of torque with more than 200lb ft on offer over such a wide rev band but that's not a huge amount for modern engines - and it showed on some of the hills where mechanical sympathy made you change up from second to third but soon revert to second.

You notice the engine first and then the steering. Complaints were made about torque steer in earlier 164s but in the Q4 torque is taken from the front wheels in part according to steering angle and torque steer is banished. It's hard to tell that the car's brain is busily switching torque from front to rear - all you notice is that there's traction and grip all the time.

The 164 is a substantial saloon yet the Q4 drives like a much smaller car and made short work of whatever challenge the mountain roads had to offer - at least it did when the suspension was on Sport setting. Unlike some variable suspension systems, where the hardest Sprt setting seems to be rock solid with no handling benefit, the Alfa's is chosen to make the car handle tautly without the penalty of a bone-jarring ride. Switch to the automatic setting and you soon realise you can't make anything like the same quick progress over tisty roads.

Large saloons are normally out of their element on a race track, unless they happen to be the radically modified examples of Europe's various Touring Car Championships, but Alfa was keen to demonstrate the 164 around Varano alongside some of its other 4x4 models. You could soon see why. Journalists let loose around a circuit quickly produce shrieks of tortured rubber as the tyres of whatever is being driven are rapidly destroyed. However, the 164 circulated with complete poise and very little noise. Even Varano's tightest corners, left and right-handers, produced none of the ploughing on that you would expect from the front-wheel-drive 164 driven at similar speed. Just how good the car is was brought home with a session in the 155 Q4 which felt tall and narrow-tracked in comparison and had but one aim in life - to understeer itself off the track. But as the 155 Q4 is quite an accomplished chassis, and first cousin to Lancia's integrale, that just shows how good this 164 is.

The sad thing is that there appears to be little chance of the 164 Q4 being imported to the UK. Driving left-hand-drive cars over here is not normally worth the aggravation but you might want to make an exception for this Alfa.

Sidebox: PRICE - Not available in the UK. DRIVETRAIN - Quad-cam V6 with light alloy block and heads and 24 valves driving all four wheels. Six-speed manual Getrag gearbox. Max power 230bhp at 6,300rpm. Peak torque 206lb ft at 5,000rpm. Manufacturer's figures 0-62mph 7.5 sec. Maximum speed 149mph.

Please email me with comments or corrections
Page best viewed at 800x600 resolution or higher