Humber · 1919–1928

Humber 15

Humber Fifteen 15 horsepower cars were medium to large cars, classified as medium weight, with a less powerful than usual engine which attracted less annual taxation and provided more stately progress. The coachwork was superbly finished, especially the tourers, and these cars were much favoured by the professional classes. They were manufactured from 1919 to 1924 and 1924 to 1927. Their former place in Humber's catalogue was bracketed in 1927 and 1928 by new cars, a much smaller engined 14/40 or late in the same year a 20-horsepower six-cylinder 20/55 of ten per cent greater capacity.

Text from Wikipedia (CC BY-SA 4.0).

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Introduction

These cars were displayed at Olympia's first postwar Motor Show in November 1919. Commentators described the design as common-sense and not sensational with evident attention to detail. The blue saloon with shining black roof and mouldings drew attention.

Fifteen .9

=== Engine === The 2.8 Litre four cylinders in line engine made in a single casting had a detachable cylinder head and was fitted with, new for Humber, overhead inlet, side-by-side exhaust valves. Their equivalent prewar car with an engine of 3.3 Litres had twin overhead camshafts. Bodies. The 15.9 was available as a saloon or a 5-seater tourer. There was no door for the driver because the brake lever and gear change lever were to his right and the spare wheel and tyre were fastened to the outside of the car at the same point. A saloon landaulette was added to the standard range and it also showed the care and forethought put in to give comfort and convenience. Between front and back seats it had a glass partition with sliding panels and there was an extra fold-away seat in the rear compartment which might be turned to face either side. Brakes suspension steering. The hand lever to the driver's right by the change-speed lever operated internal expanding brakes on the back wheels, the foot brake pedal operated a contracting band on a drum just behind the gearbox. A hand adjustment for wear was provided for both rear and transmission brakes. The Times thought the suspension was not quite free from fore and aft movement but was otherwise satisfactory and comfortable on a rough road. The springs were set with a minimum of camber, they were half-elliptical, set on top of the axles and from 1923 Hartford shock absorbers were fitted at the back. Steering was by worm and complete wheel and could be adjusted for wear Test. A road test of Humber's Fifteen horsepower five-seater open tourer by the motoring correspondent of The Times resulted in published comments along the following lines. The Fifteen is an expensive car but, without an employee for the purpose, an owner who dri

Fifteen 40

The 15-40-hp, a lightly revised 15.9, was displayed at the Olympia Motor Show in October 1924. Engine. The Times noted some trouble had been taken to dampen engine vibration. The engine and separate gearbox were on a subframe. The engine was flexibly held by two sets of enclosed springs at the front end and at the back by semi-circular steel trunnion blocks. These blocks were secured by spring-loaded bolts. This way the engine was held firmly in a fore and aft position but could swing to the limits of the two sets of enclosed front springs. Bodies. Each body now had four instead of three doors. The rear seats were wider incorporating the space above the wheel arches, the mudguards were built closer to the wheels to reduce mud splashing. The saloon landaulette's solo occasional seat was now a pair and they folded into the partition below the glass division. Brakes, suspension. The 15-40-hp was fitted with Humber-Perrott semi-servo front wheel brakes. The driver's foot pedal still worked the transmission brake and now the front wheel brakes as well. A floating shoe gave the semi-servo effect and it relied to some extent on forward motion. Applying the brakes when backing the car received only half the force. Front axle and stub axles were strengthened to accommodate the higher loads from braking, to the same end the springs were wider and there was a new cross tube linking the dumb irons (forward ends of the main longitudinal chassis members). Front brake adjustment was carried out by jacking up that end of the car and the hand-operated nuts turned until equal pressure was provided to each wheel. The following year a compensating device was installed between the two sets of brakes. Shock absorbers were now fitted to the front as well as to the back suspension. Test. When

Sections adapted from Wikipedia (CC BY-SA 4.0); text is shortened. Read the full article for the complete history and citations.

Specifications

name: Humber 15.9
Manufacturer: Humber Limited
Production: 1919–1928
Body style: 5-seater open tourer (AllWeather), 3-door saloon (spare is by driver), saloon landaulette, chassis only also available
Layout: FR
Engine: 2815 cc Straight-4
Transmission: enclosed Ferodo-lined clutch, a short Hardy disc-jointed shaft to the four-speed gearbox which is held at four points with its control by driver's right hand, open propeller shaft with one fabric (front) and one metal universal joint to bevel driven rear axle
Wheelbase: 123.5 in, Track 57 in
Length: 173 in
Width: 69 in
Kerb weight: Saloon 31 cwt, 3472 lb
Predecessor: Humber 20
Successor: Humber 15/40
sp: uk

Specification summary from Wikipedia (CC BY-SA 4.0). Check the linked sources for citations.

More photos

Sources

Wikidata — https://www.wikidata.org/wiki/Q28126634CC0 1.0 · retrieved 2026-10-01
Wikipedia — https://en.wikipedia.org/wiki/Humber_15CC BY-SA 4.0 · Text © Wikipedia contributors; revision 1294925853 · retrieved 2026-10-01
Wikimedia Commons — https://commons.wikimedia.org/wiki/File:1923_Humber_15.9_h.p._saloon_(10252764193).jpgCC BY-SA 2.0 · Photo: Clive Barker from Selsey, West Sussex, U.K. · retrieved 2026-10-01
Car Model Index — https://models.autoculturesociety.com/Compiled record. Sources that do not permit reuse are not copied; this index is credited instead.