A question of taste: BMW 635CSi vs Jaguar XJ-S vs Bitter SC

By Martin Buckley

| 21 Jan 2021

Classic & Sports Car – A question of taste: BMW 635CSi vs Jaguar XJ-S vs Bitter SC

A coupé is a purely emotional purchase, in which such nebulous concepts as rarity, snob appeal and image take precedence over any sort of clear-headed practicality.

Shifting the balance of compromises by making packaging subordinate to visual appeal, a coupé flatters the ego and massages our vanity in ways that most buyers of such things would not care to admit.

A really handsome, lantern-jawed two-door job gives out the subliminal message that its owner has abandoned the practical world of the humdrum saloon (and the chores associated with them) for a vehicle that prioritises style over function, indulgence over duty.

A pair of long doors and a low-cut roofline make you, the owner, look richer and sexier: even if ‘Coupé Man’ can’t actually hear the crumpet swoon at 50 paces then at least he thinks he can – and that’s really all that matters.

The airy BMW looks upright beside the low-slung Jaguar

Coupés invariably represent a fiscal sleight of hand on the part of their manufacturers, in that they feel justified in charging you more for giving you less: less space, poorer vision (not always, but usually) and less sheet metal.

Certainly you can believe, if you like, that your sleek coupé is faster and more nimble than the four-door it is based upon, but there are no guarantees; potentially flabbier and often more rust-prone, many a classic coupé turned out to be the inbred and less refined cousin of the highly productionised saloon that spawned it.

Perhaps I have some underlying insecurities because I have always been an unapologetic fan of the two-door versions of almost anything – from cheese-laden 1970s status-seekers of the Granada Ghia/Toyota Crown ilk to those higher-priced types of more noble lineage that, at the height of their powers, owed no piece of road to almost any car in the world.

Well balanced and grippy, the 6 Series feels like a grown-up BMW compared to the hooligan 3 Series

Enter the Jaguar XJ-S and BMW 6 Series. Launched in the mid-’70s, they squared up nose-to-nose for 13 years, both tasked with replacing much-loved (but no longer US-market crash-safe) two-door ’60s forerunners.

The Paul Bracq-designed 630/633CSi was exactly the sort of crisp, efficient luxury coupé buyers expected of the Bavarians.

They virtually sold themselves, particularly once the 635CSi was launched in 1978 with the 3453cc (later 3430cc) version of BMW’s canted-over in-line ‘six’ that, with 215bhp, was good for 140mph.

Karmann built the 6 Series bodies at first (until BMW realised that they were earning a rusty reputation not far adrift of the legendarily crusty E9 coupés), with underpinnings shared by the E12 and (after 1982) E28 5 Series saloons.

The mechanicals employed the classic BMW formula of semi-trailing arms at the back and MacPherson struts at the front.

“In some ways, this 3.6 is the best XJ-S I’ve driven”

Meanwhile, the XJ-S was starting to look like Jaguar’s first serious misstep since the MkX.

Rather than a like-for-like E-type replacement, here was a new kind of GT Jaguar that, even in the mid-’70s, was about as politically correct as Bernard Manning at an Antifa gig.

With its magnificent V12 engine and 11mpg thirst, it was seen by many as neither a worthy successor to the E-type nor a truly ‘practical’ coupé in the rational German idiom.

But what its critics failed to acknowledge was that this near-silent 150mph 2+2 outshone its Teutonic rivals in everything but space and detail finish.

It could now be argued that vanity was the only reason to buy an Italian V12 when this British Leyland supercar was more accomplished in almost every department.

Replacing the iconic XK unit was a tough brief for the AJ6

The trouble was, the XJ-S was not selling. Widely perceived as thirsty and unreliable, it was nearly dropped in 1980 only to be saved at the last moment by the introduction of the thriftier V12 HE versions and boss John Egan’s blitz on quality.

The 1983 introduction of the 3.6-litre AJ6-engined model at last gave Jaguar a car that could look the sportier six-cylinder German competition in the eye.

Its standard-fit five-speed Getrag manual ’box gave the 225bhp XJ-S 3.6 real-world performance that was the equal of the 5.3-litre V12 in all but top speed, but with the potential for mpg in the mid-20s.

With firmer suspension, more steering feel and a cheered-up, walnut-trimmed cabin, the 3.6 gave Jaguar’s once troubled coupé a second chance, although few would have predicted a 21-year production run and total sales of 110,000.

The neat-handling Bitter

Over in Germany Erich Bitter, the tuner and former racing driver, eyed the situation with curiosity and thought he saw an opportunity.

Having enjoyed modest success with his Baur-bodied, Opel Diplomat-based CD coupé through to the late ’70s, Bitter thought he spied a niche for a new model based on the latest Senator and Monza range, the first Opels to seriously challenge BMW and Mercedes-Benz standards of big-car sophistication.

He had a vision of a full four-seater coupé with the fashionably angular lines of the latest Italian exotica, but made with German standards of build quality – its body panels stamped out accurately, not hand-beaten.

Bitter spent £2.5million on the project, mostly on stamping presses, and even styled the new SC himself with a certain amount of assistance from Michelotti and the GM design department.

A capacity stretch gave the Opel straight-six the muscle it needed to take on the might of BMW and Jaguar

With Baur by then fully committed, Bitter sought help from Italy: the first 79 bodies were built by Carrozzeria Ocra, the rest by Maggiore.

Paint and trim were completed in Italy, too, after which the shells were shipped back to Bitter’s workshops in his home town of Schwelm, where 20 operatives added the Opel Monza’s 3-litre drivetrain, suspension and brakes.

Production was initially at a rate of just one car per week, but this got a boost when the 210bhp 3.9-litre model, stroked to 3848cc by Porsche tuner Mantzel, arrived in 1984 – after which almost every SC was specified with this bigger version of Opel’s cam-in-head straight-six.

Set up to sell 400 SCs a year, it was obviously never Bitter’s intention to go head-to-head with the Jaguar and BMW two-doors of this world.

However, by the end of the ’80s just 462 SC coupés had found homes as the market for faux exotic oddities contracted to almost nothing.

Large pop-up lamps date the angular Bitter, but it’s an otherwise coherent design

Had the plan to sell the cars in North America (through Buick dealers) gained momentum then the SC story might have had a happier ending.

Perhaps the model would have evolved into a family of Bitters that the convertible and four-door saloon versions predicted; just 22 of the former and five of the latter were built.

It comes as a surprise to learn that as many as 26 SCs were sold new in the UK, this silver 3.9 currently owned by Damian O’Brien being one of them.

Bought unseen in 2018, it has been subjected to a huge amount of recent fettling by Mercedes-Benz specialist Edward Hall.

Car number 334 was registered new in the UK in late 1985. Its long-term first owner was a US-based British financier who also had the convertible and saloon versions of the SC in the States, and kept this car in an underground car park in London.

This Bitter has been brought back to best

It had suffered from a lack of use combined with bodged attempts at maintenance – the idle system had been hacked about and lean running had resulted in six cracked pistons.

One engine rebuild later – plus endless work trying to make the sunroof watertight – it now goes as well as it should.

One delicious irony of owning a Bitter in 2021 is that it is now a more difficult car to keep on the road than the Ferrari 400 it superficially looks like.

“Sourcing quality, correct-spec parts and accurate set-up data has been the major challenge,” says O’Brien.

The Bitter’s distinctive alloys hint at its Opel origins

As a shape the Bitter holds its own beside the BMW and the Jaguar, with neatly resolved rubber bumpers, clean pop-up headlamps and a pleasing lack of chrome jewellery.

Only the heavy window frames on the doors and the sense that it sits too high – on tyres that look too small – break the spell of exoticism.

Inside, the lavish ruched leather seats – made by the same Italian firm that supplied the interiors for the Maserati Biturbo – give the SC an opulent flavour, although this is somewhat undermined by what appears to be the wholesale adoption of the boxy plastic Senator/Monza dashboard with its slightly brittle switchgear.

Even the unlovely steering wheel is a direct lift from the big Opel, likewise the column stalks and the shifter for the three-speed GM Strasbourg automatic (only 10% of buyers opted for the Getrag five-speed manual).

Inside the Bitter SC are thickly padded seats, plus a cheap dash livened by bespoke dials

Under the bonnet, the long, deep, all-iron straight-six looks similarly unglamorous, but performs with a lusty enthusiasm that is a match for the BMW – although it is neither as sweet nor free-spinning as the creamy, refined 6 Series.

Luckily, the Bitter inherits the composed road manners of the Senator/Monza: its excellent straight-line stability, smooth and powerful brakes and unruffled body control.

Kickdown in the four-speed automatic is responsive, giving access to real mid-range meat, and the power steering strikes a nice balance between low-speed handiness and high-speed precision – with the bonus of a really useful turning circle.

In fact, the Bitter feels like a great car – a real GT rather than just a flash coupé.

Each of these coupés has something to offer

Until, that is, you drive the BMW.

This fully optioned 1986 635CSi automatic has been exhaustively rebuilt by owner Matthew Rees using genuine BMW parts, and is thought to be the best in the UK. I’ve certainly never seen or driven a better one.

Outwardly, it is of course very handsome in that glassy tradition of BMW coupés. The massively glazed roof gives the beautifully wrought interior an upbeat feel and the wraparound dash looks exhaustively thought out and expensively constructed in pleasing, muted plastics.

The solidity of the car can be sensed through the steering, and the seat of your pants, before the 635 has even turned half a wheel length.

Sitting in its six-way powered seats, the relationship between pedals, steering and your eyeline on the outside world feels just right.

The superb layout, fit and finish of the BMW 635CSi’s cabin

Under way, the BMW wafts serenely along, as pleasant to drive at low speeds as it is at higher ones, other than the slightly jiggly ride.

Where the Bitter’s straight-six rumbles, the BMW’s sings to 6300rpm, pulling hard to its redline as it goes through its four-speed ZF automatic gearbox, changing up at 60, 85 and 100mph for a zesty rate of acceleration not far adrift of the five-speed manual version.

With the fully matured, lower-pivot version of BMW’s semi-trailing-arm rear suspension, getting the tail out of shape takes a concerted effort, while with 3.4 turns lock-to-lock, the modestly boosted steering is well matched to the 635’s suave rather than aggressively brutish character.

The appeal of the big coupé endures

Sitting inches lower than the 6 Series, the XJ-S is a car that looks better now than it did 30 years ago.

With its huge bonnet, slinky lozenge-shaped headlights and swoopy rear buttresses, there is no mistaking it for anything else.

You limbo down into its intimate cabin, where the front seats are less luxuriant than the German cars’ and the rears are strictly for kids.

Being a later 3.6-litre AJ6-engined car, this beautifully maintained 124,000-miler benefits from the post-’87 tweaks aimed at improving engine refinement.

Initially you miss the turbine smoothness and hush of the V12. In fact, it would be fair to say that Jaguar’s alloy-block, multi-valve twin-cam lacks the silky feel of the BMW ‘six’, never mind its 5.3-litre sibling.

Yet it has a lusty character of its own, punching hard to its conservative 5700rpm redline with a throaty sense of purpose that is in no way coarse.

It might be a little cramped in the Jaguar’s cabin, but the interior of the XJ-S has more charm than the others in this test

Its 225 horses are also a good match for the well-plotted ratios in the five-speed Getrag manual ’box, where you can cruise at 70mph in top at 2250rpm or make commanding 50-90mph overtaking manoeuvres in its versatile third.

Not a Japanese flick-switch job, this, yet there is something engaging about its long, precise but slightly notchy movements.

The ability to choose just the right gear for any given situation immediately makes the XJ-S a slightly more alert-feeling car than either Bitter or BMW.

With its higher front spring rates and re-valved assistance for the rack-and-pinion steering, the 3.6 asserts itself on the road like no XJ-S before it, feeling much lighter on its feet and turning in more keenly yet with hardly any deterioration in the ride, which is subtly firmer but still beautifully compliant and very quiet.

Can the coachbuilt Bitter take on the might of Jaguar and BMW?

It’s interesting to see (having previously had very little to do with the six-cylinder versions) how the AJ6 engine changed the personality of the car, mostly for the better.

In some ways, this 3.6 is the best XJ-S I’ve driven; it just lacks the dark romance of the full-fat Leyland-era 5.3.

The Bitter SC is an interesting oddity, built just around the time when this sort of boutique vehicle was being made increasingly irrelevant by cars such as the XJ-S and the 6 Series in a world that no longer truly understood or needed such machines.

It steered a strange course between handbuilt ‘charm’ and reliable off-the-shelf banality that, in the end, failed to satisfy either those customers who might have wanted the SC for its curiosity value, or those who were looking for a credible alternative to a 6 Series.

Each looks very different from the others, when seen from behind

In fairness, the Bitter got far nearer to the standards set by the BMW than you might expect (falling down on the easy bits, such as its ugly dash), but in period the only true German alternative to a 635 was a Mercedes-Benz SEC.

By the time production ended in 1989, a total of 86,216 6 Series had found happy homes and subsequent attempts at building a big BMW coupé proved what a hard act it was to follow.

Effortlessly superior in important matters such as fit, finish and thoughtful design, the 635CSi was technically a more conservative car than the XJ-S – and in many ways not such a good one to drive.

Yet there is an air of mature and elegant practicality about the 6 Series that would make it my pick.

Images: John Bradshaw

Thanks to Swansea Airport

Factfiles

BMW 635CSi

Sold/no built 1978-’89/86,216 (all 6s)
Construction steel monocoque
Engine iron-block, alloy-head, sohc 3430cc straight-six, Bosch fuel injection
Max power 215bhp @ 5200rpm
Max torque 228Ib ft @ 4000rpm
Transmission five-speed manual or four-speed automatic, RWD
Suspension independent, at front by MacPherson struts rear semi-trailing arms, coil springs, telescopic dampers; anti-roll bar f/r
Steering power-assisted ZF recirculating ball
Brakes discs, with servo and anti-lock
Length 15ft 7¼in (4755mm)
Width 5ft 8in (1725mm)
Height 4ft 5¾in (1365mm)
Wheelbase 8ft 7¼in (2626mm)
Weight 3241Ib (1470kg)
Mpg 19-25
0-60mph 7.5 secs
Top speed 140mph
Price new £25,290
Price now £15-40,000*

Bitter SC

Sold/no built 1981-’89/462
Construction steel monocoque
Engine all-iron, cam-in-head 3848cc straight-six, Bosch fuel injection
Max power 210bhp @ 5100rpm
Max torque 257Ib ft @ 3400rpm
Transmission five-speed manual or four-speed automatic, RWD
Suspension independent, at front by MacPherson struts rear semi-trailing arms, coil springs, telescopic dampers; anti-roll bar f/r
Steering power-assisted worm and roller
Brakes discs, with servo
Length 15ft 9in (4800mm)
Width 5ft 7in (1702mm)
Height 4ft 4in (1320mm)
Wheelbase 8ft 8in (2642mm)
Weight 3439Ib (1560kg)
Mpg 23
0-60mph 8.4 secs
Top speed 137mph
Price new £26,950
Price now £20,000*

Jaguar XJ-S 3.6

Sold/no built 1982-’91/8867
Construction steel monocoque
Engine all-alloy, dohc 3590cc straight-six, Lucas electronic fuel injection
Max power 225bhp @ 5300rpm
Max torque 239Ib ft @ 4000rpm
Transmission five-speed manual or four-speed automatic, RWD
Suspension independent, at front by wishbones, coil springs, telescopic dampers rear lower wishbones, driveshafts as upper links, twin spring/damper units
Steering power-assisted rack and pinion
Brakes discs, with servo
Length 15ft 11in (4853mm)
Width 5ft 11in (1791mm)
Height 4ft 2in (1265mm)
Wheelbase 8ft 6in (2951mm)
Weight 3927Ib (1781kg)
Mpg 18-24
0-60mph 7.2 secs
Top speed 136mph
Price new £19,248
Price now £6-15,000*