Jaguar became the official name of the old SS concern, and the famous "100" models were amongst the best-sellers of the 1937 - 1939 period. Much adverse criticism was directed towards the Jaguars prior to WW2, as vintage enthusiasts were apt to regard them as particularly suitable for promenade work, and as the Bentleys of Wardour Street, Soho. But nothing could have been farther from the truth. The Jaguars had proved themselves to be really fast sports cars, and had done extremely well in competitions.
Despite the fact that Jaguar had never officially raced its products prior to WW2, pre-production machines received such a battering at the hands of the test drivers that the cars were turned out with every possible improvement incorporated in them. The builders were not slow to learn from actual racing cars, and their performance was extraordinary for such low-priced sports cars. Possibly, actual road-racing might have helped to steady the front end a bit more when cornering at high speed, as weight distribution would have been considerably improved as a result. Nevertheless, the Jaguars did hold the road well, and very few unblown cars could catch them once the back wheels start revolving.
Both the "100s" were developed from the old side-valve cars, particularly the 2.5-litre SS "90." The 2.3,-litre car had a 2663-c.c. (73 x 106-mm.) six-cylinder power unit, whilst the 3.5-litre car employed an engine of 3,485.5-c.c. (82 x 110-mm.). Both engines had overhead valves, operated by pushrods, twin S.U. carburetters, and were installed in a chassis having a wheelbase of only 8-ft. 8-in. At the time, the 3.5-litre had the shortest wheelbase of any British sports car built over 3-litres. Chassis construction followed along conventional SS practice, and semi-elliptic suspension was used front and rear. Braking was by Girling, being progressive yet extremely powerful. The 2.5-litre car had a genuine maximum speed of 90 m.p.h., whilst the larger car was one of the few unblown British cars capable of exceeding the century mark.
