In 1937 the T5 Combat Car was accepted in to service as the M1 Combat Car. The first 58 vehicles had a “D” shaped turret with two machine guns, but later examples had an octagonal shaped turret with a 3rd machine gun designated the M1A1 Combat Car. The new turret was offset to the side.

The US M1 & M2 Combat Car Variants

M1 – the original variant. 89 built.
M1A1 – new octagonal turret instead of a D-shaped one; increased distance between the wheel bogies. 17 built.
M1A1E1 – engine replaced by Guiberson T-1020 diesel. 7 built.
M2 – new Guiberson diesel engine and trailing idler. 34 built.

The US M1 & M2 Combat Car Spec’s

Armaments: x1 7.62mm Machine Gun & x1 12.7mm
Armour: 16mm steel
Crew: 4
Dimension: Length 4.14m / Width 2.4m / Height 2.3m
Weight: 5.89 tonne
Engine: Continental W670-7 250hp petrol
Top Road Speed: 72km/h
Operational Range: 161km