In 2012, Ginetta introduced a full
GT3 version of the G55, which featured a
Ginetta Racing-built 4.35 litre
V8 engine in place of the Cup's 3.7 litre V6. Previously, they had used the Cup-spec car in GT3 races. The car's first win came at the Donington Park round of the Britcar series; with
Team LNT and
Optimum Motorsport taking a G55 one-two. A G55 GT3 was used by
United Autosports for the 2012 Britcar 24 Hours, with the team entering
Richard Dean,
Lawrence Tomlinson,
Mike Simpson and
Tom Kimber-Smith as their drivers. The team contested under the Team LNT banner, and finished 21st overall, and third in Class 1. The G55 GT3 was announced as one of the official cars for
Project CARS simulator in August 2012, alongside the G50 and the
Ginetta G40 Junior. Ginetta showcased both models of the G55 at the 2013
Autosport International Show. For the
2013 British GT season,
IDL Racing announced they would be entering a G55 GT3 in the series (in conjunction with CWS), whilst two Works-run cars were also entered. ==GT4==