|Manufacturer||Austin Motor Company Limited|
|Production||by May 1928—mid 1932|
|Body and chassis|
|Body style||saloon, limousine|
|Engine||3,397 cc (207 cu in) Straight-six or 3,610 cc (220 cu in) Straight-4|
|Transmission||single-plate clutch; four-speed and reverse gearbox; propellor shaft to back axle with helical-bevel gearing|
|Wheelbase||Ranelagh 11' 4", 136 in (3,500 mm) Mayfair 10' 10", 130 in (3,300 mm) Whitehall 10' 0", 120 in (3,000 mm) Carlton 10' 0", 120 in (3,000 mm) Track 4' 8", 56 in (1,400 mm)|
|Kerb weight||36 cwt 4,032 lb (1,829 kg)|
New body October 1926
The car that was destined to succeed the Twenty, the six-cylinder 20/6, was announced at the October 1926 London Motor Show with production really starting in early 1928, and until 1930 the two different engines were sold alongside each other, but 1929 would be the last year of full production for what was now called the 20/4.
There was a 12-volt electrical system for lighting and starting. Timing was at the back of the engine. From there on the off-side were driven in-line the generator, water-pump and magneto. Reported refinements for the 1929 Motor Show included: chromium plated exterior fittings, Triplex glass, improved (dome type) "mud wings (front mudguards) and new gas (sic) and ignition control levers "neatly placed above the steering wheel". For 1930 the specification included Biflex magnetic dip and switch headlights and wire wheels.
The engine, clutch and gearbox, which was centrally-controlled, all formed one assembly that was held in the frame by two brackets with a rubber-lined frame at the front. The rear axle was three-quarter floating.
Steering is worm and worm wheel type. Beneath the hand wheel there is a convenient ring-operated horn switch.
Behind the gearbox there was a "locomotive" transmission brake operated by a hand lever on the off-side of the gear lever. The brake's shoes were to some extent self-adjusting but might be regulated by two hand screws. "This brake is intended to be more than just a parking brake". The four wheels had brakes operated by rods from the brake pedal . Compensation was made so that balance was preserved in the back and front sets of brakes. The application was partly taken by rods but finally by cables. The brake drums were enclosed and have outlets for water or oil. The front braking mechanism was simple, there was only one arm which had anchorage above the pivot pin and did not turn with the wheel. The cams were at the bottom of the drums and the steering pins were hollowed to allow the necessary expanding control.
The front and back springs were half-elliptical. At the back they were carried under the axle. Both sets had lubricating gaiters and shock absorbers. There was no camber to the forward springs. There were no stops behind the back shackles.
- Open Road tourer 4-cylinder £425
- Open Road tourer 6-cylinder £525
- Carlton saloon 4-cylinder £495
- Carlton saloon 6-cylinder £595
- Marlborough landaulette 4-cylinder £475
- Ranelagh limousine or landaulette 4-cylinder £575
- Ranelagh limousine or landaulette 6-cylinder £675
Seats are comfortable. The speedometer only showed up to 60 mph, within the engine's capacity. No sign of overheating. Clutch satisfactory, lower gears much quieter than on previous Austins. Brakes suspension and steering were not at all bad but could be made better.