The Crossley 20 hp was introduced in 1909. It became the 20/25 in 1912 and continued until it was replaced by the 25/30 in early 1919. Some 1918 cars were fitted with the later, more powerful, engine used in the 25/30 and designated as "X types" and often also had a V-shaped radiator .  

The number made for civilian use is not known but is estimated at 2100. At least 6000, possibly as many as 10,000, were made for military use. Before about 1919 chassis numbers were not segregated by model type and  are in the range up to 12000.  The "X-types" had numbers prefixed with an X. Many ex RFC tenders were later rebodied as cars or buses and given new civilian chassis numbers.

The engines were numbered and date stamped and engine numbers and chassis numbers were close but not usually identical. As an example, engine number 11152 is stamped July 1918.

(Photo - Donald Chadwick)	A 1910 20hp with front wheel brakes. (Unusually we know the chassis number for this car, 710, with engine number 709.)
	20hp with Mann Egerton Three-quarter Landaulette body £640 (1912)
	20/25 Crossley bodied Landaulette photographed outside the factory in 1917
	20/25 5 seat tourer
	20/25 Tender with ambulance body
	20/25 Tender with light lorry body
	20/25 Staff Car. The wheel discs are not standard.

Many cars were supplied in chassis only form to independent coach builders. The above are a selection of the body styles produced by Crossley and other coach builders

The prices quoted are from contemporary advertisements.

Engine/gearbox/transmission

Body/chassis

capacity 4531cc cylinders 4 pair cast. Fixed cylinder head. bore 4 inches (100mm) stroke 5 1/2 inches(140mm) compression ratio  4 to 1 RAC Horse Power 25.6 carburettor 40 mm Smiths valves side lubrication pressure to 5 main bearings ignition Magneto max power 40 bhp at 1500rpm fuel consumption (typical) 13-15 miles per gallon max speed (approx)  55 miles per hour Gears 4 speed right hand change Clutch cone Drive Shaft Torque tube Rear axle fully floating axles straight cut bevel gears ratio of 4:1 and others

wheelbase 10 feet 6 inches length 13 feet 6 inches track 4 feet 6 inches width overall 5 feet 3 inches weight 18 cwt (chassis) steering  worm and quadrant suspension - front semi elliptic springs suspension -rear three quarter elliptic springs brakes rear wheel only (front brakes optional. The front and rear brakes were not coupled. The front were operated by pedal, the rear by lever) wheels/tyres 875 x 105 or 880 x 120 (20hp). Twin rear tyres spoked to a single Rudge hub on many military versions.

© Malcolm Asquith 2006