Fast Facts

• Engine: 2969cc/6-cyl
• Power (bhp/rpm): 180/5800
• Torque (lb ft@rpm): 182/4200
• Top speed: 134mph
• 0-60mph: 8.7sec
• Fuel consumption: 22mpg
• Transmission: 4-speed auto
• Length: 15ft 6in (4.72m)
• Width (inc mirrors): 5ft 8in (1.72m)
• Weight: 3290lb (1494kg)
• Books: Monza, Senator & Royale, the enthusiasts’s guide by Trevor Alder. Transport Source Books (OOP)
• Clubs: GM6 Spares Co, Cornwall (used parts). 01736 810 500, www. stores.ebay.co.uk/gm6sparesco Opel Classic Parts, Germany. 0049 180 500 9097, http://stores.ebay.co.uk/ Opel-Classic-Parts-Center Vauxhall dealers

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Most coupés that look fantastic, offer little in the way of practicality. Not the Opel Monza and Royale though, which can seat fourin comfort, cross continents with ease while all the time oozing understated class. When the Royale and Monza appeared in the late Seventies, they were designed to take on Merc’s mighty W123 coupé, the CE, along with the Lancia Gamma coupé. When it came to driver enjoyment, space, equipment and performance, the Monza had its rivals licked – especially when you threw build quality into the mix. Now the Monza is a classic it’s even more appealing, as values are relatively low and there are some superb examples out there. But there’s a lot of rubbish too…

What to look for?

The MacPherson strut tops rot, leading to the suspension collapsing; repairs must be seam-welded for strength. Other rot spots include the mounting points for the fuel pump, the rear suspension trailing arms and the fuel tank along with the sills, wheelarches, door bottoms and rear quarter panels. Make sure that the sunroof surround hasn’t rusted (quite common).  The powerplant’s lubrication system is its weakness, the fi rst sign of wear being noisy hydraulic tappets, usually around 80,000 miles. Carburettors and injection systems can leak fuel, while injected cars can run erratically once the ECU gets wet or the auxiliary air valve sticks. Poor running is also caused by poor connections within the wiring loom multi-plugs in the engine bay. Listen for rumbling or whining with a manual gearbox and check it doesn’t jump out of gear as these Getrag gearboxes are very costly to overhaul. Rear wheelbearings are weak; they’ll whine when they need replacing and it’s a horrible task. Rear coil springs can break on the bottom coil with replacement springs now rare. Brake hoses are hard to fi nd and power steering hoses can rupture; they’re scarce too. Cars built from 1983 are the ones most likely to be suffering from broken switchgear, fi xtures and fi ttings; some bits are available on a used basis. Electrical problems often stem from the wiring loom going brittle and because these cars invariably have a lot of kit fitted, you need to check that everything works. Sometimes the fault is electrical, but it’s often electronic, making faults harder to diagnose.

Values

The newer and more highly specifi ed the car, the more sought after it is, which is why the Monza GSE is the most desirable. Carburetted 2.8 Royales aren’t sought after, so good ones can be just £700 – although they’re rare. Be wary of cars stored for long periods; the best ones are used regularly. A GSE is £2000+, sought after for its sportier chassis and exterior looks, extra performance and standard equipment. Tarted-up cars that look good but hide a multitude of sins beneath are common. Solid, well-maintained cars can be bought for £1000-£1500, while some of the desirable older(chrome bumper) cars appear with very optimistic prices; despite their value for money don’t pay over the odds.

Driving one

With a straight-six up front and a choice of automatic or manual transmissions, the Monza and Royale offer power and torque aplenty, guaranteeing a relaxing drive no matter how long the journey. Things are made even better by the fact that these cars were based on the range topping Senator, so they’re well-appointed – and thanks to a wheelbase shortened by just an inch, there’s no shortage of room for four inside.