The next series of cars had a completely new, longer and stiffer chassis with innovative coil sprung independent suspension. This chassis was designed by John Thurner and would form the basis of the one used by TVR up to the launch of the 2500M cars in 1972. The Mark III also received a new front end design, with the grille mounted higher and featuring some rudimentary chrome trim. The Mark III and the later Mark III 1800 cars used BMC
B-series engines, either 1622 or 1798 cc respectively, although Ford or Coventry Climax units were also available for the earlier Mark III model. The larger capacity 1798 cc MG 'B' series engine became standard equipment around September 1963 although this more powerful engine appears to have been available as a customer-specified option prior to that date. At some point during 1963 the rear of the car was reprofiled to include a number plate mount. In 1965 the latest version of the car became available as the 1800S with a cut off, square back (called a 'Manx tail' after the similarly tailless
breed of cat) and round rear light clusters from the
Ford Cortina. The 1798cc
B-series engine remained but the chassis used for the 1800S and all subsequent Granturas was a modified version that, through an alteration to the line of the top chassis rails, allowed more space for the engine to fit in. This was an alteration made to the Grantura chassis to allow it also to be used as the basis for the new
Griffith, a car that sported a V8 engine which was larger both in capacity and physical dimension. After a pause in production during late 1965, under Martin Lilley's new ownership the 1800S reappeared in early 1966 rebadged as the Mark III 1800S. This was quickly followed by the new Mk IV model. The Mk IV featured a longer wheelbase, more luxurious trim and a larger fuel tank and was the first TVR to benefit from Martin Lilley's influence. Approximately 300 of the Mark III, Mark III 1800, 1800S and MkIV cars were built (estimated to be 60 of the Mark III, 30 to 35 of the Mark III 1800, 128 of the 1800S / Mark III 1800S and 78 of the Mk IV) before being replaced in 1967 by the
Vixen. taillights ==The TVR Grantura in pre-1966 historic racing==