Fast Facts
- Best model: 3.8 S-type manual o/d
- Worst model: 3.4 S-type automatic
- Budget buy: All 420s
- OK for unleaded?: Can be but speak to specialist
- Will it fit in the garage? (mm): 4750 x 1683 mm
- Spares situation: Not as good as Mk2
- DIY ease?: Not quite as good as Mk2
- Club support: Typically excellent Jaguar
- Appreciating asset?: Prices are starting to rise
- Good buy or good-bye?: It can only be the looks as an S-type is a superior car to the Mk2 and yet cheaper, even more so 420 is close to XJ6 standards –

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A superior and more sophisticated alternative to the hallowed Mk2 but cheaper to buy if not to run or restore. Body parts can be specific, problematic and extremely expensive, especially for 420, but a clever, classy buy all the same
It may surprise many to learn that the unwisely sadly often overlooked S-type actually outsold the Mk2 when these models were produced in tandem during the 60s. In 1965, for example, well over double the number of S-types (9741) were made; that more Mk2s were sold was due to its longer production run, meaning S-type buyers, owners or simply drivers were a clever lot.
Not much has changed over half a century since the S-type and the more upmarket 420 bowed out to make way for the soon-to-be launched XJ6 because while this ‘shrunken MkX’ may lack the cachet of the Mk2, it’s by far the better car, understandably really considering its E-type rear suspension to give this Jag what Mk2s always lacked, great grip and a quality ride. So why has the S-type and the later 420 addition always been pooh-poohed and regarded as a second-rate Mk2 alternative? Looks and image presumably (they were invariably driven by criminals on the silver screen) because the S-type is the car the Mk2 could and should have been. So why not use this to your favour because not only is the S-type a nicer car to drive, but it’s nicer on the wallet too as values trail Mk2s by a handsome level. However, we reckon it won’t always stay this way – look how values of the Mk1 has overtaken its replacement for example.
History
1959 Rumour has it that Jaguar was looking at a more upmarket saloon not long after the Mk2’s launch to bridge the gap between this saloon and the soon-to-be launched MkX limo.
1963 The somewhat hurried S-type saloon surfaced in October as the logical bridge between the ranges. The hull was mainly Mk2 albeit with a flatter roof line and a MkX style rear end to boost boot space plus it also meant that the excellent independent rear suspension, first seen on the E-type, could be used. The shell to be extensively re-engineered to achieve this at a cost of almost 350lb in weight, however. To balance the odd looks, the front end was tweaked with new front wings incorporating novel hooded headlamps and slimline bumpers. Inside a MkX-style interior and kit gave the car a more upmarket image.
1965 At launch, the S-type was criticised for an appearance which looked as though Lyons designed it in a bit of a hurry. Even so, changes introduced this year were more mechanical, such as the substitution of the old Moss gearbox in favour of Jaguar’s own although the vast majority of S-types were automatics. Jaguar resisted the logical step of replacing the 3.8-litre XK engine with the 4.2 despite having done so on the E-type and MkX, nor felt the need to use that excellent Daimler 2.5 V8 (an S-type 2.4 was never offered due to lack of performance).
1966 A downgrading of both the Mk2 and S-type ranges saw Ambla used instead of leather trim, cheaper carpets and a deletion of the traditional standard fog lamps came in the shape of the new 420 (and similar Daimler Sovereign), that August which at last featured the MkX-style nose that Lyons always wanted the S-type to wear but didn’t get round to due to the car’s notably short development time. Mechanically, 420 used a 245bhp twin (not triple) carb tune of the enlarged XK engine. Other improvements included a new front axle incorporating a better power steering and new three pot disc brake callipers. The Daimler version was the best appointed and an auto only whereas the Jaguar could be had as before as a manual plus the option of overdrive.
1968 The 420/Sovereign was essentially a needed stop-gap to make up for the delayed XJ6 launch and bowed out in June to make way for the new Jag although the Daimler version survived well into 1969. However, the S-type also received some important changes in 1968, such as the 420’s Marles Varamatic power steering, while the 420 auto (of which two-thirds soaked up the sales) sported a lower axle ratio (3.5:4) to improve engine response but the useful limited slip differential was no longer fitted on all models.
Driving and press comments
You’d think that the addition of the E-type’s independent rear suspension would have enthusiasts drooling over S-types, but on the road the more skittish Mk2 remains the most preferred thanks to its sportier feel, helped by success in motorsport, no doubt. It did, after all, win the first-ever European Touring Car Championship way back in 1963. Yet Jaguar test drive legend Norman Dewis told Classic Motoring that he liked the S-type better for its more secure handling and better ride. It depends what you are after – if you favour comfort and cruising most of all then go for the S-type.
There’s little argument that the S-type feels far more polished and planted compared to a Mk2 thanks to that superior rear end plus the ride is a lot smoother. One respected weekly went overboard in 1965 by regarding the S-type as one of the most comfortable cars ever produced – and a marked improvement over the leaf sprung Mk2.
Granted lighter weight and better aerodynamics means the Mk2 remains the more fleet-of-foot cat. A 3.8 S-type is only marginally quicker than a 3.4 Mk2 but on the other hand the 420 is a bit of a Q car, the manual passing 60 in a highly creditable 9.2 seconds and hits almost 120mph if you want but with “little performance gain over the automatic” remarked one road test.
In 1967, Motor magazine summed up the 420 (Automatic) saying that despite its patent E-type pedigree, “This is not a car with any strong sporting pretensions” although contradicted itself somewhat by reckoning the manual version test car (a rare Daimler Sovereign, incidentally) was more sporting than many sports cars! “This is one of Britain’s best cars, which means one of the best in the world”, said a patriotic Autosport.
As a result of the S-type being seven inches longer than the Mk2, the cabin feels decidedly roomier thanks to a flatter roof line and steeply raked rear screen to increase headroom. Slightly thinner MkX front seats liberated a touch more legroom, too while that elongated tail meant a more usable 19cuft of boot space against the Mk2’s measly 12cuft.
Economy will never impress mind; a wallet-wobbling 15.3mpg from a 3.8 automatic model back in 1964, (after rocketing to 60mph in over 14 seconds) reckoned one weekly. Strangely, manuals fared little better when overdrive should have come into its own, perhaps the added weight meaning more right foot being applied more of the time?
When Autocar tested a S-type 3.8, it remarked that this new Jag “stands out on its own, between family transport and executive limousine… a car which will look right anywhere, be it in a farmyard or luxury hotel”. Its verdict was “an outstandingly good car in its class… although related to the Mk2, is a model in its own right”. The 420 was even better and many specialist and owners reckon it is close to XJ6 standards – what a smoothie that Daimler V8 engine would have made?
Values and the marketplace
What price is an image? Typically, the superior S-type realises around 65 per cent the worth of an equivalent Mk2 and it has to be a superb example (the 3.8 being the most desirable) to break the £20,000 barrier. Most fair cars go for around half of this, while restoration runners start from £4000. The strangely unloved 420 is the most affordable of them all being in the region of two-thirds the price of an equivalent S-type irrespective of Jaguar or Daimler badge.
Having owned S-types since he was 17 and currently holding a pair of the best left, it’s fair to say that specialist dealer Robert Hughes is a massive fan and he says that if he only could keep one classic then it would be an S-type and not necessarily a 3.8 either as he says anyone new to the car would find it hard to tell the difference in performance between the two engines.
The Weybridge, Surrey dealer cites the Jag’s great comfort, refinement and handling that’s on par “with a 1992 XJ12” as its best points although admits that it is highly unlikely that the S-type will follow in the tyre tracks of the Mk1 and actually overtake the Mk2, value-wise.
Robert Hughes says the later 420 (and the more upmarket Sovereign) has a different character to the S-type and is more akin to an S1 XJ6, albeit more compact, so it depends what you want although adds that he doesn’t like modified cars, many of which he feels aren’t done properly and rob the true spirit of a car, and not simply S-types either.
Peter Bell of the JEC says the S-type is a much underrated Jaguar and well worth considering against a poorer condition Mk2 for similar money. “I always advise to buy on condition rather than model,” he told us and that’s the best advice of all as restorations are costlier than for a Mk2 but for less financial gain or sense.
Improvements
Do you take the view of specialist Robert Hughes? He may well have a point because while uprating an S-type for modern use is similar to improving the Mk2, fewer owners do so. Did you know that S-types and 420 use a superior engine cooling set up, for example?
As the S-type is appreciably heavier and slower than a compatible Mk2, more performance may be appreciated and there are various well known routes to take, but using later 340 head is a good, cost-effective tweak along with E-type cams – or fit a XJ6 S3 head. If you’re happy with stock spec, then consider an electronic ignition and set the ignition up with a strobe to find that sweet spot which is said to improve things noticeably.
As the S-type is more of a cruiser than the Mk2 just overhauling the suspension and renewing the Metalastik mountings usually works miracles along with new springs and dampers; you can go firmer to control cornering roll but you also don’t want to spoil the serene ride either. If the brakes are in good order, they’ll suffice, but the 420 sports a much superior front set-up that’s worth fitting to earlier S-types (and Mk2s) for that matter before considering aftermarket kits which while better may not be warranted. Motor found that by upping the tyre pressures to a bloated 34psi it improved the big saloon’s agility no end.
Overdrive makes the going easier on manual (you can fit the XJ6 S3 five-speed with a bit of graft and lots of cash) but autos can sound and feel fussy. The answer is to fit a taller axle ratio (there’s a wide choice) or a later Jaguar four-speed ’box which has an ‘overdrive top’ but the job is likely to run into thousands though.
What To Look For
General
- S-type and Sovereign may be largely Mk2 derived but the 420 has some XJ6 components as well. And due to rarity and past lack of popularity, body and chrome parts are becoming hens’ teeth to source with many, such as 420 front wings, now obsolete.
- Because they are not as coveted as Mk2s and it’s only now that serious money is being spent on them, expect to find some old bodges and dodges and don’t expect originality to have been a priority.
- The 3.8 was the best selling S-type by an appreciable margin (a third) and don’t be surprised to find models uprated to 3.8 spec. Similarly, you may find 420s fitted with XJ6 engines, usually identified by the later fluted cam box covers.
- There’s even more wood and leather to restore than on a Mk2 so don’t underestimate the cost of a refit. A new dash (padded on the 420) can cost thousands for example while a full interior makeover can run to £10,000 and S-type values don’t generally dictate such expenditure. But one day they may.
Body & chassis
- As with the Mk2, the main areas for rot are the chassis box sections and the front cross-member, particularly at its ‘crow’s feet’ which are welded to the valance and cross-member. Check these areas with utmost care as repairs are involved and expensive so bodging was common over the decades.
- Sills, both inner and outer, are common corrosion areas so lift the carpets up and have a good poke around – replacements (try Martin Robey) are just over £300 per side, but it’s the fitting that bumps up the bill. Also inspect the floor pan and boot floor. While crawling underneath (and you should) check the IRS rear suspension cradle and attachment points – if they’re corroded then the whole assembly can pull away under hard acceleration.
- Repairs to the rear are more complex than a Mk2’s due to the double-skin rear bodyshell. Check the floor and also the twin fuel tanks which seem more prone to rust and subsequent leaking than the Mk2.
- Serious but not so terminal are the door bottoms (you can get new skins for the rear ones at under £60 a go from Martin Robey), wings and the front ‘snout’, the latter of which can rust badly and is frequently disguised with some deft filler work and a splosh of underseal for good measure as replacements are so expensive.
- S-type front wings cost the thick end of £2700, £1000 less for a major repair ‘snout’ panel from also Martin Robey or David Manners but at least they are available; unlike 420s and are bodged accordingly using XJ6 repair panels which are a tolerable but hardly identical match. It depends how much a stickler you are for originality. A lower rear wing repair panel works out at £330 from David Manners with the jacking point adding £100.
Engines
- Listen for over-silent tappets (meaning the cam shims are worn and need replacing – a DIY but involved job that’s best carried out when doing a decoke), and rattly timing chains, the bottom ones being the worst to replace.
- Oil pressure on a healthy XK unit should be in the region of 40lbsqin at 3000rpm when good and hot. Watch for valve guide and bore wear (smoking under hard power or at idle) but don’t be over-concerned by excessive oil usage: XKs like a drop of full-bodied 20W/50 at the best of times – try a 20W/60.
- On the other hand, they also love to leak the stuff! Prime areas are warped cam covers and – more likely – a leaking rear crank oil seal. You’ll have to live with the latter unless really bad because it’s an engine out job to rectify with upgraded replacements and will cost around £1000. You might wish to carry out an overhaul while you’re at it; a proper job costs around £4000.
- Overheating XKs are not unknown of course but hardly as common as many would have you believe either. The S-type featured a superior cooling system to the Mk2 and the heater should be better too. Problems stem from furred up waterways, caused by low-quality anti-freeze gumming up the channels over the years. Take the car for a good long run to check that all is ok.
Running gear
- S-types are hefty old things so as expected, it’s the springs and dampers that wear the most. See that the car sits straight and true. If replacing springs, ensure that you get the right ones as the heavier S-type used different rates to the Mk2 and Daimler V8 for that matter.
- Similarly the steering joints suffer from more wear, as do the steering boxes (roughly £250 and £500 for a PAS). There’s a cluster of bushes that deteriorate; polybushing is popular as they last longer and give a more precise feel at the expense of ride and refinement.
- The rear suspension is located on a special sub-framed cradle with insulating rubber bushes, that perish, causing rear steer and they’re very awkward to replace (as are the inboard rear brakes). It’s worth biting the bullet of a £2000 bill if a specialist does it, as a re-bush job transforms the car’s road manners at a stroke. Polybushing is tougher, and improves handling but affects ride quality so it’s down to personal choice and many like the standard feel.
- That suspension means inboard rear disc brakes are part of the package and apart from the difficulty of renewing the pads, they are prone to picking up oil from a leaking differential (very common).
- Rear callipers are unique to this model to counter the added weight and dearer to repair or overhaul than on a Mk2. According to Peter Bell, technical advisor to the JEC, XJ6 ones are the best alternative and considerably easier to obtain.
Transmission
- Although the Jaguar gearbox is better (both units are characteristically heavy and slow to use) watch for weak synchromesh causing gear crash when shifting up or down on both. If overdrive is fitted, check it works quickly and smoothly (may just need a service and oil change though).
- Rear axles are known to leak oil and are harder to fix than on a Mk2 due to the independent rear suspension set-up plus the bearings in the alloy hub carrier can fail, leading to clonking on the move.
- Listen for undue noise and roughness from the limited slip diff, if still fitted, it’s quite possible the axle ratio may have been changed on an automatic. A fully rebuilt axle will cost £2000 or more.
- The Borg Warner three-speed auto boxes are inherently lazy affairs but also smooth and longlived. Inspect the fluid: it should be clean and not smell ‘burnt’. If it does then it suggests wear. Check for slipping, slow, clunky take up and loss of ratios. Try the box in all the manual modes but bear in mind that on the later (Daimler-sourced) Borg Warner Type 35 unit, ‘D2’ position allows the car to move off in second for smoother, slower progress so don’t assume there’s something wrong with it.
- Clutch replacements are a major job and beyond the realms of many home mechanics because the engine and transmission have to come out as one or you can drop the front axle assembly. And it’s real heavy duty stuff and not for the novice…s
Three Of A Kind

Daimler V82.5/250
Perhaps the Daimler is more in character with the S-type than the Mk2, because the accent is on smoothness and refinement rather than haring about. What that lovely V8 lacks in outright pace against the XK (although it’s much better than the 2.4) it compensates in its sweetness and flexibility. The interior is more akin to the S-type’s cabin too, and both score over the normal Mk2 in terms of value for money but prices are starting to rise.
Rover P5
A fine cruiser that’s a roomier Mk2/S-type alternative if not so seductive. But what it lacks in sportiness makes up for everywhere else, including value for money. Very smooth both in straight six and the more respected V8 form with the former having the edge for refinement if not speed. Values are steadily climbing for good ones but on the other hand there are a lot of poor ones around as rust is rife and a P5 costs Mk2 money to restore without the gains.
Austin 3 Litre
The replacement for the fondly loved Westminster and Vanden Plas is essentially a bigger-bodied top and tailed BMC 1800 powered by a detuned MGC engine and rear-wheel driven with self levelling rear suspension. Another self-destruct idea from BMC with under 10,000 sold before its 1971 demise, it offers masses of space and comfort for a pittance. Good ones are starting to attract buyers after something different – that the 3 Litre certainly is.Verdict
The more you look at an S-type or 420, the more enticing they become. Here’s a ‘Mk2’ with all the comfort and refinement of a MkX without the girth, better, if not so ‘sporting’ handling, fine power steering and brakes, plus the lust of the 4.2-litre (420) and all for a third less of a compatible Mk2. It’s simply criminal not to take advantage of this.
Classic Motoring
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