As the swinging ‘Sixties drew to a close the Mini was reaching what would prove to be the peak of its success. Although approaching 10 years old the little car was still selling well, and would in fact continue to set sales records into the early ‘Seventies. The formation of British Leyland in 1968 saw a round of rationalisations and design changes take place that saw the Mini actually make a per-unit profit for the first time, while in June 1969 the two-millionth Mini was built – the first British car to reach this milestone.

Despite this success the wrinkles were showing through the design and there were plenty of flaws and ‘niggles’ left over from the original 1959 design that BMC didn’t have the will or the ability to fix. With Leyland’s money and new management the time had come to give the Mini a much-needed overhaul.

The result was the MkIII Mini, launched in October 1969. The most obvious external changes were winding rather than sliding windows and internal door hinges, which tidied up the car’s appearance. By this stage Alec Issigonis was no longer in control of the design office at Longbridge and he intensely disliked the changes made to ‘his’ car, going so far as to retrofit sliding windows to his own MkIII car. However, the new version was much more refined and, crucially for BL, was cheaper to build. It was available with the 848cc and 998cc A Series engines. It was decided that the Mini had a sufficiently powerful name to stand on its own right, with the different Austin and Morris versions giving way to plain ‘Minis’, badged as the ‘850’ and the ‘1000’ respectively.

British Leyland management had no time for the BMC craze for badge engineering. The ‘booted’ Minis (the Wolseley Hornet and the Riley Elf) cost a great deal to make and sold only around 120 examples a week. At the same time BL objected to the royalties they were paying to John Cooper on every Cooper-badged Mini sold. At £2 per car on a car with minimal profit margins the company was keen to end this arrangement.

BL’s marketing team, led by its sales manager (an American with the distinctive name of Filmer Paradise) came up with a solution in the form of the ‘Clubman’. This was a luxury version of the Mini with sculpted and padded seats, more trim, better soundproofing, more standard equipment and more comprehensive instrumentation. It had a restyled nose, based on the look of the upcoming Austin Maxi, with a square front and a flat-top bonnet. There were a few inches of length added to the front of the car, which improved access to the ignition system (always a problem on the Mini). The Clubman was sold as the 850, the 1000 and with the 1275cc engine, which was badged as the 1275.

The Clubman replaced the Wolseley and Riley variants, and the next stage was a sporting version to replace the Cooper. This became the 1275GT. As well as being royalty-free the new name established some much needed commonality with the imminent Austin and Morris 1300GT models. While the cost cutting measures that went into the MkIII saw the lower-priced Minis lose their Hydrolastic suspension, the Clubman and the 1275GT retained the fluid-based system to provide a much better ride, as befitted their more luxurious image.

As a replacement for the iconic Cooper models the 1275GT was considered rather inadequate. To minimise costs the 1275GT used the drivetrain straight from the ADO16 1300, but development of the 1300GT’s twin-carb 70 horsepower power unit lagged behind the Mini, so the 1275GT made do with the 59 horsepower version with a single 1.5-inch venturi SU carb, of which there was excess production capacity. BL’s rationalisation meant that the existing 65 horsepower 1275cc engine from the Wolseley 1300 model couldn’t be used!

The use of the ADO16’s drivetrain also meant that the 1275GT had the same gear and final drive ratios as its more pedestrian siblings, while the Cooper that preceded it had a wider spread of gears and a raised final ratio. Coupled to the poor aerodynamics this meant that the 1275GT struggled to its top speed of a distinctly mediocre 87mph. BL deflected criticism by saying that the new version was cheaper to run and to insure and that it was supposed to be a different sort of car – a punchy cruiser rather than a rally-derived miniature sports saloon. Few people were fooled and the 1275GT never matched the sales success of its Cooper predecessors.

To get an idea of how all these variations stack up we’ve gathered together two very early MkIII Minis – an 850 (representing the car at its most basic) and a 1275GT, which was the range-topper. Both cars are, in different ways, low-mileage examples. The 1971 850, owned by Michael and Paul Cretten, is the result of a seven-year rolling project that included a full bare shell respray. Tanya Field’s 1970 1275GT has just over 60,000 miles on the clock and is an entirely original example. This bodes well for experiencing these cars as they would have appeared to the buyer in 1970.

The 850 is definitely the classic Mini in appearance. Purists may mourn the lack of many of the little features that mark out the original cars but to anyone else it is the stereotypical old Mini with tiny wheels, plain hubcaps, and chrome grille and bumpers. It’s a car that would blend in to any ‘Seventies town centre and I imagine few people would really have noticed the difference between the 850 and an original MkI.

The interior of this car differed slightly from standard. A factory-fresh 850 had the familiar full-width parcel shelf with a lone speedometer in the middle. Michael and Paul have added a vinyl-clad dashboard with the speedo flanked by the smaller Smiths temperature and oil pressure gauges. This is exactly the sort of personalisation that Minis have undergone since day one, and there are other entirely in-period mods such as a Paddy Hopkirk sports throttle pedal. The seats are modern replacements in black with cream piping to match the rest of the car. Despite the added trim the little car’s use of space is just as remarkable as before, and even a 6’ 2” driver like myself can find a comfortable, if rather unusual, driving position.

This car, being made two years into the run, has a few features that the first MkIIIs didn’t have. The most significant is a fully remote gearchange by rods rather than the set-up on the earlier cars, which in 850 form had a direct ‘magic wand’ gearchange. Early cars had flick-switches for the wipers and lights, while this car has proper rocker switches. The ignition key is also column-mounted rather than lurking in the centre switch panel.

Turning that key and applying a little throttle stirs the 848cc A Series engine into life. This car has both its original and an aftermarket set of carpets, which removes a lot of the ‘biscuit tin’ acoustics of a basic Mini, but a lot of this is down to standard-fit parts such as the padded door trims. The updated gearchange doesn’t need the usual dab-into-third trick to quieten things down before selecting first. With the traditional ‘hair trigger’ throttle response of an A Series, the 850 feels very eager when pulling away, with the unmistakable whirr of the straight-cut bottom gear that no classic Mini experience is complete without.

On ‘dry’ rubber suspension the 850 has the usual tight ride that anyone who has piloted a Mini will be familiar with. It does a surprisingly good job of absorbing big bumps and it takes a slight misjudgement with avoiding a pothole to make things actually uncomfortable. However the 850 is a car that never really settles. While it takes the worst out of a road surface it is fidgety, with a tendency to pitch and bounce, as you would expect from a short car on small wheels. There is also prodigious amounts of road noise and tyre roar is transmitted as vibration into the bodyshell and thence to the driver’s backside.

Of course that short-travel suspension does wonders for handling. The MkIII 850 loses none of the Mini’s ‘big go-kart’ handling (a cliché, but it really is the only way to describe it), with the same tactile steering and tenacious grip that made its predecessors such a hit. The A Series engine puts out 33bhp and works best in its mid-range. Coupled to the low gearing and the much-improved shift action, this makes the 850 perfectly suited for nipping around town at 30/40mph. The one weakness is the brakes, which are still drums all-round. With all the other controls being so easy and direct to use, the firm shove needed to get the unassisted brakes to start biting is rather out of place. They work well enough given the car’s modest weight.

On the open road the 850’s bottom-of-the-range specification starts to show. The low gearing that makes it perky at low speeds makes it rather breathless when keeping up with faster traffic. Despite the added internal trim of this example it still sounds rather frantic, even if the car is much happier than its occupants. The 850 loses ground when asked to climb hills, although the superlative handling means you can maintain that hard-won speed in the corners.

The 1275GT is as ‘Seventies as David Bowie on a Space Hopper working a three-day week. This example is in Bronze Yellow (actually orange). It sits on silver-painted miniature Rostyle-sculpted steel wheels, sports stripes with the legend ‘MINI 1275 GT’ along its flanks and has a black plastic grille with red ‘GT’ badges. It is not a subtle car and is a stark contrast in every way to the functional minimalism of the 850. The modernised front end certainly gives the car a purposeful, chunky look but when viewed in profile the extra bonnet length and the front overhang does upset the proportions, although this may just be because the standard Mini shape is so familiar that seeing it ‘the same but different’ looks odd.

The inside of the 1275GT is perfectly in keeping with its styling, with lots of black vinyl, seats made from perforated ‘leather effect’ vinyl, a three-spoke steering wheel with the 1275GT logo on the boss and a three-gauge instrument cluster in front of the driver. The dial pack includes a rev counter, which was a first for a Mini. The dark trim and the extra dashboard padding means that the GT lacks the 850’s airy feel to the cabin, but in a sports-orientated model this is no bad thing. However the driving position is, of course, the usual for a Mini and is distinctly unsporting.

This early GT has its ignition key mounted back in the centre of the dash. The bigger A Series engine speaks through a slightly larger exhaust pipe with a nice growl at idle. The throttle response is still immediate but the clutch is much heavier and fiercer in action. This car has the earlier semi-remote gearshift. The opinion on these seems to be ‘very nice if you get a good ‘un’ and this one seems to be a good ‘un. The action is quite heavy but it has a slick shift with a very narrow gate.

On a wet gravel car park I pull away with a bit of wheel spin before I’ve got used to the clutch. The most immediately obvious difference is to the ride quality. Although the GT had slightly stiffer springs than the Clubman, the ride is still hugely better than in the 850. It highlights just how much of the apparently ‘rough’ ride of the ‘dry cone’ Minis is actually down to uncontrolled pitching rather than harsh springing. The Hydrolastic system almost totally damps this out, leaving the 1275GT feeling like a much bigger car. A bigger car with rather taught suspension, granted, but the stability and finesse is there. Better still, the 1275GT hasn’t lost any of the more basic car’s handling and grip. There is still no body roll to speak of and the GT can be hustled around roundabouts and twisting lanes even when they’re wet.

The 1275GT produces a multi-instrumental soundtrack. The exhaust growls at low speeds, barks when provoked in the mid-range and even obliges with a little crackle on the overrun. There’s the usual first gear whine, but the transfer gears set up a rather addictive shriek under load, so you can pretend the car has a supercharger when accelerating. There is also just the right amount of induction roar; enough under heavy acceleration to sound sporty, not enough to be obtrusive in the cruise.

The problem is that to make the car perform as its looks suggest it should, you really have to work it hard. At heart it is not a high-performance model and what seems to be very brisk acceleration is partly down to the fact that the GT makes such a fuss about doing it, with lots of noise and revs for relatively little gain in speed courtesy of the low gearing. The 1275GT certainly doesn’t seem to have nearly twice the power of the 850. The combination of low gearing, a decent power output and a light car means that the 1275 can maintain its pace very well and never feels like it’s being overworked, although it also means that it sounds quite frenetic.

The 1275GT is, therefore, a rather ill-defined car. It’s not especially fast, it handles very well but no better than a normal Mini, it’s physically comfortable, but too unrefined to suit the ‘GT’ part of its name in the literal sense. In fact its one real advantage is its ride comfort, which was also available on the Clubman and in a few years would be gone all together when Hydrolastic was deleted. It is certainly not a suitable replacement for the Cooper models and doesn’t even stack up to BL’s own marketing claims. In many ways the 1275GT is a Mini that removes a lot of the classic Mini features (ease of driving, interior space, economy, the looks and a lot of the charm) while providing nothing to replace it. In typical BL fashion it is a car that is perfectly good when considered in isolation (a fun to drive, small, comfortable car with crisp handling) but that completely falls apart when compared to its competition and its position in the market.

That leaves me to consider the 850. It is the complete opposite of the 1275GT in that it adds little to the essential Mini formula, but this is a good thing because that formula has always worked so well. The few changes that it does incorporate; some more trim, winding windows, a better gearshift, really only make it easier to use. It’s just much closer to the Mini concept of a spacious, cheap to run small car and for that reason if I could take one of these cars home with me it would be the 850 rather than the more valuable 1275GT.