The XJ6, using the 2.8-litre (2,792 cc (170.4 cu in)) and 4.2-litre (4,235 cc (258.4 cu in)) straight-six cylinder versions of Jaguar's renowned XK engine, replaced most of Jaguar's saloons – which, in the 1960s, had expanded to four separate ranges. Apart from the engines, the front and rear suspensions carried over from previous models as well: the widest version of Jaguar's IRS unit from the Mark X, and the subframe-mounted independent front suspension first seen in the 1955 Mark 1, with new anti-dive geometry.