Along with the closely-related Velox and Cresta, the Wyvern EIX was the first completely new postwar Vauxhall. The 1442cc engine was carried over from the previous Wyvern but the bodywork was thoroughly modern and very American in its look, with a lot of flashy chrome up front and a curved windscreen, something unusual for the era. The increased weight of the new styling blunted performance so, from 1952, a 1507cc engine was fitted. This increased power from 35bhp to 40 or 48bhp. Aside from tweaks to its exterior, the Wyvern continued in this form until 1957.
info from Octane