Following changes to the companies management TVR launched a revised Grantura model in 1964, the Grantura 1800S. The new car was really a revised version of the Grantura III featuring styling changes, a new engine and better weight distribution.
The 1800S used a 95bhp BMC B-series engine (the same unit found in the MGB) as its powerplant. The main change to the bodyshell was the cut-off "Manx Tail" rear end. This styling change resulted in the spare wheel being located above the boot floor, this meant that the wheels extra weight was no longer behind the rear axle.
In 1966 the Grantura 1800S was updated and renamed the Grantura 1800S IV. Main differences were confined to minor trim changes, however an attractive wood dash was a welcome addition. Production of the "IV" was to be short lived, it ended in 1967 with the arrival of the new Vixen.