Editing BMC ADO17 (section)

==Development==
===Mark I===
The Austin 1800 was developed at BMC as a larger follow-up to the successful [[Mini]] and [[Austin 1100]] under the ADO17 codename, ADO being an abbreviation for [[Amalgamated Drawing Office|Austin Drawing Office]]. Additional [[Badge engineering|badge-engineered]] Morris 1800 and Wolseley 18/85 variants were launched in 1966 and 1967 respectively, catering for the BMC dealerships selling those marques. The 18/85 name had previously been used on the [[Wolseley 18/85 (1938 to 1948)|Wolseley 18/85 of 1938 to 1948]].

The car was unconventional in its appearance in 1964, with its large glasshouse and spacious, minimalist interior including leather, wood, and chrome features plus an unusual instrument display with ribbon speedometer and green indicator light on the end of the indicator stalk. There was a chrome "umbrella handle" handbrake under the dashboard parcel shelf, and the two front seats met in the middle and could be used, on occasion, as a bench seat. Both [[Alec Issigonis]] and [[Pininfarina]] worked on its exterior. The car's technical internals were also unconventional and ahead of their time, including [[Hydrolastic]] [[Suspension (vehicle)|suspension]], and the application of inertia-controlled brake-force distribution, by means of a valve which transferred braking force between front and rear axles, as a function of sensed deceleration rather than as a function of fluid pressure. An interesting feature was a tail/brake/indicator night dipping system. A resistance circuit was connected in such a way so that when the sidelight circuit was energised, the resistors dimmed the tail/brake/indicator lights so not to blind or dazzle following drivers. The [[Unibody|unitary bodyshell]] was exceptionally stiff, with a torsional rigidity of 18,032 Nm/degree.<ref>[http://copeland.id.au/?p=67 "Austin 1800"]. Automobile Engineer. December 1964</ref>

Progressive improvement was a feature of most cars in this period, but the number and nature of the changes affecting the early years of the Austin 1800 looked to some as though the car had been introduced with insufficient development. In December 1964, a month after its launch, reclining front seats and the option of an arm rest in the middle of the back seat were added to the specification schedule.<ref name=Motor197002>{{cite journal |title=Spot check: BLMC 1800| journal=Motor |pages=22–24 |date=14 February 1970}}</ref> A month later, in January 1965, the final drive ratio reverted to the 3.88:1 value used in the prototype, from the 4.2:1 ratio applied at launch: this was described as a response to "oil-consumption problems". The same month also saw the indicator switch modified.<ref name=Motor197002/> At the same time, higher gearing and reduced valve clearances reduced the published power output by {{convert|2|bhp|abbr=on}}, but cured the "valve-crash" reported by some buyers when approaching top speed on one of Britain's recently constructed [[motorway]]s.<ref name=Motor197002/> The manufacturer quietly replaced the "flexible, flat-section dipstick" which, it was said, had caused inattentive owners to overfill the [[sump]] after inserting the dipstick back-to-front so that the word "Oil" could not be seen on it.<ref name=Motor197002/>

Subsequent modifications included changing, repositioning and re-angling the handbrake in October 1965,<ref name=Motor197002/> removing the rear anti-roll bar and rearranging the rear suspension at the end of 1965, at the same time adjusting the steering to fix a problem of tyre scuffing,<ref name=Motor197002/> and fitting stronger engine side covers in January 1966, along with modified engine-mounting rubbers which were "resistant to de-bonding".<ref name=Motor197002/> February 1965 saw water shields fitted to the rear hubs,<ref name=Motor197002/> and the car's steering rattle cured by the judicious fitting of a spacer,<ref name=Motor197002/> while the propensity of early cars to jump out of first and second gears was solved by the fitting of a "synchroniser".<ref name=Motor197002/>

Further improvements followed the launch of the Morris 1800 early in 1966. Gear cables were revamped to deal with "difficult engagement" of first and third gears in cold weather,<ref name=Motor197002/> and the seat mountings were adapted to increase rake in May 1966.<ref name=Motor197002/>

In June 1967, without any fanfare or press releases, a modified version of the 1800 began to arrive at dealers, with repositioned heater controls, a strip of "walnut veneer" on the fascia, and separate bucket seats replacing the former split bench seat at the front.<ref name=Autocar196706>{{cite journal |title=News and Views: New trim for BMC 1800 |journal=[[Autocar (magazine)|Autocar]] |volume=126 (nbr 3724) |page=58 |date=29 June 1967}}</ref> Other criticisms seem to have been quietly dealt with at the same time, including the fitting of more highly geared steering, which needed only 3.75 rather than 4.2 turns between locks,<ref name=Autocar196706/> although the modification had applied to cars produced since September 1966 and, in the case of Australian cars, some time before that.<ref name=Motor197002/>

This was also the point at which the car received a differently calibrated dipstick, giving rise to rumours that engine problems on some of the early models had resulted from nothing more complicated than the wrong calibration of the dipstick, causing the cars to run with the wrong level of engine oil. The manufacturer insisted that the "recalibration" of the dipstick was one of several (unspecified) modifications, and urged owners not to use the new dipsticks with older engines.<ref name=Autocar196708>{{cite journal |title=News and Views: Austin 1800 assessment |journal=Autocar |volume=127 (nbr 3730) |page=49 |date=10 August 1967}}</ref>

A nickname of 'Landcrab' was given to the car by some car enthusiasts, derived from the car's unusual proportions, being much wider and lower than most other cars in its class. The car's successful use in endurance rallies came about because, while the car was never particularly fast, its strong bodyshell and sophisticated suspension allowed it to reliably maintain competitive average speeds over long distances on poor roads. The car's stance, strength and slow-but-sure nature over rough ground put the BMC rally crews in mind of a [[terrestrial crab]]. The nickname stuck and became widespread in the press and public.{{citation needed|date=August 2020}}

The ADO17's doors were later also used on the [[Austin Maxi]] and larger [[Austin 3-Litre]] models, as well as on the [[Panther De Ville]].

<gallery widths="200px" heights="150px">
File:Austin 1800 in W-wa blue f.jpg|Austin 1800 (Mark I)
File:Austin 1800 in W-wa blue r.jpg
</gallery>

===Mark II===
In May 1968, a Mark II version was launched. This featured a cheaper and more conventional interior, revised front grilles and other trim, and for the Austin and Morris models the slim, horizontal rear lights were replaced by vertical "fin" lights which gave a family look along with the smaller [[BMC ADO16|ADO16]] range. The Wolseley retained its unique rear lights. Other changes included a higher second gear and final drive ratio for the manual transmission, and conventional suspension bushes replaced the far superior roller bearings fitted to the Mark I. The compression ratio was increased and maximum power output boosted by 5&nbsp;bhp to a claimed 86&nbsp;bhp.<ref name=Autocar1968>{{cite journal |title=Mark II BMC 1800s |journal=Autocar |volume=128 (nbr3768) |page=16 |date=2 May 1968}}</ref> The Mark II also had larger wheels.<ref name=Sedgewick144>Sedgewick p144</ref>

In 1969, the sills and doors from the 1800 (with Mark II exterior handles) were used on the bodyshell of the otherwise new [[Austin Maxi]]; apart from that, both models have little interchangeability.

The 1800S twin carburettor 95&nbsp;bhp engine came in from October 1968.<ref name=Sedgewick144/> By 1970, a {{convert|97|bhp|abbr=on}} "S" model with twin SU HS6 carburettors, a 120&nbsp;mph speedometer and sporty-looking badging was available.
<gallery widths="200px" heights="150px">
File:Austin 1800 Automatic 1969.jpg|1969 Austin 1800 Mark II
File:Morris 1800 (829778368).jpg|Morris 1800 Mark II
File:1969 Wolseley 18-85 (10794972395).jpg|1969 Wolseley 18/85 Mark II
</gallery>

===Mark III===
Further, less dramatic modifications heralded a Mark III version in 1972. This had another change to the front grille (now a shared style for the Austin and Morris) and interior improvements, including a conventional floor-mounted handbrake.<ref name=Sedgewick144 /> At this point, six-cylinder versions were introduced&nbsp;– the Austin 2200, Morris 2200 and Wolseley Six. While 1800 versions of the Austin and Morris were continued, the Wolseley 18/85 was dropped.
<gallery widths="200px" heights="150px">
File:Austin 1800 Mk III 1798cc first reg Jan 1973 rear three quarters.JPG|Austin 1800 Mk III
File:Morris 1800 1972.jpg|1972 Morris 1800 Mark III
File:BMC ado17 generations front.jpg|Morris 1800 Mark I (on left) and a later Mark III model; front comparison view
File:BMC ado17 generations rear.jpg|Morris 1800 Mark I (on right) and a later Mark III model; rear comparison view
</gallery>
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