The first big breakthrough was the launch in October 1948 of their new record-breaking engine design in their XK120 sportscar to SS Jaguar 100.
It was powered by a new twin overhead camshaft (DOHC) 3.5-litre hemi-head six-cylinder engine designed by William Heynes, Walter Hassan and Claude Baily. The XK100 4-cylinder 2-Litre version had broken records in Belgium travelling at 177 mph.
It had a slightly more streamlined appearance than models, but more important was the change to torsion bar independent front suspension and hydraulic brakes.