Road test

The Opel Senator and Monza

Superb handling, performance, comfort and appointments help justify an apparent high price

Opel’s new Senator and Monza put General Motors’ European offshoot firmly on the upper rungs of the quality car market ladder, pitched in price against such well-bred status symbols as the middle range BMWs and Mercedes and Jaguar XJ 3.4. The four-door, six window, Senator saloon comes into the UK at £9,975 and the three-door Monza coupe at £10,250. It’s a hard and fussy market in the dizzy heights of the five figure bracket and while the Senator and Monza tested undoubtedly justified a high price, I can’t help sympathising with Opel’s marketing team, who have one major hurdle to overcome in their new found aspirations: the image in a name.

The Monza and Senator are available on the German market with a choice of either 2.8-litre, carburetter straight-six engines or 3.0-litre injection versions. Only the big injection engine is available in the UK, the smaller engined models being sold under the guise of the Vauxhall Royale. Other than a 40 b.h.p. power deficiency, the Royale saloon and coupe have an almost identical specification to the Opel models, yet cost some £2,000 less, pitching them in the Rover 3500/Ford Granada Ghia 2.8i battle-field. These new Opels have replaced the old Commodore at the top of the UK range; a Commodore GS/E coupe gave sterling service to a colleague. In fact the Commodore lives on in Germany as a six-cylinder derivative of the current Rekord.

The new up-market Opels share an identical mechanical specification. Their latest version of the familiar camshaft-in-head (not overhead camshaft – the valves are moved by short pushrods), oversquare, in-line six-cylinder engine measures 95 mm. x 69.8 mm. in its bores, to give a capacity of 2,968 c.c. Fed by the latest Bosch L-Jetronic fuel injection, this cast-iron unit develops 180 b.h.p. DIN at 5,800 r.p.m. and 173 ft. lb. torque at 4,200 to 4,800 r.p.m. The 9.4:1 compression ratio demands four-star fuel, but maintenance is minimised by the use of self-adjusting hydraulic tappets and transistorised, contactless ignition. This engine drives the rear wheels through a three-speed GM automatic gearbox and a split propshaft. Four-speed manual transmission is available to special order on UK Monzas (not Senators) at no extra cost, an option apparently offered as a concession to the competition department’s homologation demands.

Opel have moved from wishbone to McPherson strut front suspension for these luxury cars. An interesting feature of the semi-trailing arm independent rear suspension is the inclusion of so-called “Miniblock” conical coil springs, which have the advantage of progressive rate and reduced noise levels, for the shape prevents contact between the coils on compression. Anti-roll bars are fitted front and rear. ZF circulating ball-type power steering standard and big, power-assisted disc brakes are fitted all round, the front discs being ventilated. From the screen pillars forward the Monza and Senator bodies are identical, right down to the somewhat garish chip-cutter grille (I prefer the less fussy Vauxhall Royale design) and sloping, rectangular halogen headlights, fitted with wash/wipe facility as standard. To the rear of the pillars the Senator is a full five-sealer saloon with a conventional and enormous luggage boot. The Monza too will take five people, but not so comfortably as the Senator for those in the back, whose head and leg room Is more restricted. A big hatchback, supported on twin hydraulic struts, gives access to a reasonably commodious boot, which can be made vast by folding down the one-piece seat back, Rover-like. But unlike the Rover the Monza has only two doors in addition to the hatch, for this is meant as a sporting coupe, not a cavernous saloon. The boot space is covered by a rigid, detachable cover, part of which hinges up with the hatchback. The Monza’s roof-line is over an inch lower than the saloon’s and the coupe is 4½ in. shorter in over length at 15.4 ft., most of which is lost in reduced rear overhang, although 0.63 in. is shaved off the wheelbase, 105 in. on the saloon. The 28 cwt. Senator is just t cwt. heavier than the sporting coupe.

Most of my test mileage was spent with a Monza, for W. B. had the Senator for much of the period, but their general driving characteristics are very similar. Their engines enamoured me from the beginning with their instantaneous starting whether hot or freezing cold and smooth, unfussed “drive-away” after a night in sub-zero temperatures. The L-Jetronic injection gives perfect mixture control whatever the ambient or engine temperatures, so that this smooth and powerful straight six lacks any temperament.

Performance is considerable, not quite so fast as a 3-litre BMW perhaps, but quicker than the automatic Rover 3500, W. B.’s version of which I drove several times during the period of this Opel testing. Opel claim a 130 m.p.h. maximum for the Monza (133 m.p.h. for the optional manual version) and 127 m.p.h. for the Senator, a little bit optimistic perhaps, though the Monza was able to register 130 m.p.h. on its slightly over-reading speedometer. Less theoretical and more useful was the long-legged feel of both cars at 100 plus cruising speeds, academic perhaps to most UK customers, but essential on Opel’s homeland autobahns and an indication of how lightly this General Motors machinery has to work at the British legal limit. This is in spite of relatively low overall gearing giving 20.8 m.p.h./1,000 r.p.m. in top, which means that the engine is running almost on to the 6,500 r.p.m. red line at maximum speed. Sixty miles per hour comes up from rest in not much more than 9 sec., there being surprisingly little difference on standing start acceleration between the Senator and its lighter brother. Manual gearchanging of the automatic gearbox made little difference to the acceleration times, but to do so was to risk that usual General Motors automatic gearbox danger of banging the lever straight from second, through drive into the unprotected neutral. The light action of the Opel’s gear selector made it much easier to make this mistake than did the stiffer selector of the similarly unguarded gate of the Porsche 928 tested last month. I confess to having over-revved the Monza’s engine a couple of times for this reason and there appeared to be no ignition cut-out to safeguard the engine.

The GM automatic ‘box has received high praise over the years for all its characteristics except for that vulnerable neutral. Yet I felt that on both the test cars it was a little too eager to change up and down on a constant throttle at times when the engine’s torque characteristics felt not to need such help. Both W. B. and I when switching from Opel to Rover and back remarked on how infrequently the Rover changed gear in comparison and how smoothly the oft-criticised Borg-Warner gearbox made its fewer ratio swaps. Admittedly the lazy V8 is less demanding than the smaller, less “torquey” straight six, yet I’m sure the latter could tolerate less sensitive change-down settings. Full-throttle kickdown is heavy to apply, in common with most automatic cars tested recently, but responds quickly and when thus depressed will allow these 180 b.h.p. cars to run up to about 51 m.p.h. and 83 m.p.h. in the gears at 5,900 r.p.m.; manual hold offers seven or eight m.p.h. more at the 6,500 r.p.m. red line. The engine is beautifully smooth and quietly subdued for most of its willing rise up the rev. scale, but it does roughen up towards its maximum. Overall, however, it is a very fine, sweet-revving engine with excellent throttle response and, if I may reiterate, a satisfying lack of temperament which not only makes life easier, but also gives a feeling of solid reliability.

It is in chassis behaviour that the Opel Senator/Monza range excels most, to a degree that makes it outstanding even in the company of its compatriots BMW and Mercedes. In terms of the best compromise between ride, handling and roadholding only Jaguar surpass it in this section of the saloon car market but then Jaguar is unsurpassed in this respect by any saloon, whatever the price, so this is high praise indeed for the Opel. The general behaviour of the two Russelsheim cars is very similar, but the Monza gains in outright roadholding and slightly more sporting feel from the fitment of those marvellous Pirelli P6 tyres of 205/60 section, mounted on 15 in. alloy wheels to give more or less the same rolling radius as the 195/70 tyres fitted to the Senator’s 14 in. alloy rims. The Senator we had for test employed Pirelli CN 36 tyres; the example shown here, driven briefly for this photographic session, sported Michelin XVSs, which I preferred. The roadholding of either Opel model is excellent, that of the Monza quite superb. The degree of grip tends to accentuate initial roll in a corner, but this never rises to an uncomfortable degree. Both cars are beautifully balanced, neutral in behaviour and extremely forgiving. Few drivers are likely to push the Monza particularly beyond its limits of adhesion, but when they do they will find that the tail goes first and is very responsive to correction. Part of its forgiving nature comes from an ingenious pivot layout in the semi-trailing arm rear suspension, which minimises variations in camber and toe-in. The inside wheel can jack up a little under hard cornering, but doesn’t interfere too much with traction, which is good. A limited slip differential is available for £168.

The overall feeling of tautness which this fine suspension engenders is emphasised further by truly excellent power steering which is just right in the effort it requires (slightly more than that of the BMW 635 CSi I took over on the day we did the Senator photographic session), and in feel and response. It is practically indistinguishable from manual steering except when parking.

The ride is extremely well controlled and taut whilst remaining comfortable. The suspension copes admirably with bumps, which fail to upset it even in mid-corner and only at slow speeds over rough surfaces is there any real degree of disturbance. All the while the suspension is commendably quiet in its operation and the Senator’s overall road noise level is low. The Monza not unexpectedly suffers from more bump-thump and occasional roar from those fat P6s. Incidentally, the Monza can be ordered with a stiffer “S” suspension pack for £81.90. I drove a car so fitted at the UK Press launch last year and its handling was superb, at the expense of a harsher ride.

Backing up the impressive handling and roadholding characteristics are brakes which are nearer to Mercedes’ high standards than to BMW’s. Those 10.5 in. front discs and 11 in. rears haul these heavy cars down with reassuring powerfulness, slightly more effectively on the test Monza than the Senator, without requiring too much pressure.

These big, new Opels must be amongst the most comprehensively equipped cars on the road at any price and it is as well to take their full specification into account when comparing them with the basic prices of BMWs, Mercedes and the like, which can cost thousands to bring up to the same standard of appointment. Things like electric windows, a steel sun roof (not fitted to the pre-production test cars), exterior mirrors adjustable from inside, two stage heated front seats on the Senator, inertia reel belts (four in the Senator), four headrests on the Senator, two on the Monza, a stereo cassette-radio with aerial built into the laminated screen, tinted glass all round, headlamp wash/wipe, halogen headlamps, an electric central locking system, integrated rear fog lights are just some of the standard fitments. The Senator has an electric boot lock operable from the driving seat: the Monza would benefit from a similar installation. The toolkit puts most other manufacturers to shame. The Monza has a rear screen washer and wiper, but the test car’s heated rear screen failed when the three prong contact between the hatchback and tailgate burnt out. A modified one has been brought into production. However, the powerful demister was able to clear the big rear window area in less than ten minutes. Heating and ventilation is excellent. Vertical sliding quadrant controls, including one for the four-speed fan, give easy selection and division of heating and demisting. There are large, adjustable ventilation and side window demisting outlets at the facia extremities and a fresh-air vent in the centre of the facia.

The driving position is good except that the pedals are offset too far to the right, especially noticeable by we of the left-foot braking school: so the Porsche 928 automatic is not alone in this fault. They are too high off the floor, too, with a big jump from throttle to brake. Both models have sumptuous front seats, although for some reason that escapes me they use different types, the Recaro-built thrones of the Senator proving a shade more comfortable and having map pockets in their back rests. Inexplicably too, only the Monza’s driver’s seat has height adjustment, whereas the cheaper Senator has it on both front seats. With this fitment the seats have an excellent range of adjustment. The height adjuster is a pivoting one similar to that of the Alfa Romeo GTV, with a handle which telescopes out to give greater leverage. The Senator’s handles face rearwards, where they are easy to grasp, but the Monza’s faces forward, thus conflicting with the useful, rigid door pocket, of which the Senator has four. A stalk on the steering column allows a clever tilt facility at the hub end of the steering column for the comfortable, four spoke wheel.

The luxurious appeal of the velvet-like upholstery on the well-shaped seats and the quality of the carpeting makes the BMW equivalents look somewhat cheap. It’s a shame therefore that Opel have spoilt the ship by the use of cheap plastic finish to the facia and centre console and a preponderance of fake wood strips. This trim finish is out of keeping with the exceptionally high standard of engineering, paint finish and equipment. The facia finish and design has been kept down to that of the cheaper Opel and Vauxhall models instead of being raised to match the quality car image. At the same time, few criticisms can be levelled at instrumentation, which lives behind a rearward slanting glass panel, effectively preventing reflection. These easy to read dials include a large speedometer and tachometer, water temperature, oil pressure, fuel level and voltmeter gauges and are backed up by a substantial array of warning lights.

Apart from a large lights master switch on the right of the facia, which pulls out to switch on the interior light, and a bank of switches on the facia for auxiliary equipment, all major functions, including two speed plus intermittent wipers, are controlled by a slim stalk on the left of the steering column. Switches for the elect windows are housed in the centre console between the seats. An awkward, hook-type lever adjacent to the ignition switch has to be moved to release the ignition key.

Opel are aiming high with these new models and the standard of engineering exhibited has risen to the ambitions, especially in the area of chassis design. The Monza and the slightly better value Senator have excellent performance, road behaviour and equipment worthy of the high, price and offer a fine combination of luxury and driver enjoyment. Whether the image and the slight Americanised styling will impede the sales of these fine cars remains to be seen. – C. R.