In September 1935 SS launched their most advanced and significant new car, the first to carry the name Jaguar, though then not as the brand but as a model name – the SS Jaguar 2 1/2 litre saloon.Standard manufactured a new chassis to SS design and a Standard 6-cylinder engine was re-engineered by Harry Weslake to an overhead valve design, which Standard then manufactured specifically for SS. The rolling chassis was mated to a stylish four-door body, for sale at a very modest £385. To accompany this new model, SS also produced a smaller engined 1 1/2 litre 4-cylinder saloon using an existing Standard engine, priced at £295.

With the introduction of the SS Jaguars, all other car production ceased except for the SS1 Tourer, now produced under the SS Jaguar name.

Initially built using traditional methods of alloy and steel panels laid across an ash wooden framework, by 1938 SS moved over to all steel body production, at the same time increasing the model range to include a 3 1/2 litre version of the 6-cylinder engine. The company also produced a range of two-door drop head coupe models based on the same cars.

At this time the company produced their first true sports car named the SS Jaguar 100. Using a shortened version of the saloon chassis with the choice of either 2 1/2 or 3 1/2 litre engines, and rakish two-seater open bodywork, the car was built in very small numbers, and the model was discontinued with the advent of the war.

Production of the saloons and drop heads continued after the war, by which time the name of the company and the cars had been changed to Jaguar because of the perceived concern over the use of the insignia SS.