The one and only

1984 Invicta XJ 13 Tredecim

The Car

Invicta XJ 13 „The One and Only“ 1984

Produced in 1984 by Invicta automobile manufacturer, XJ 13 or “Tredecim” is a unique and beautiful sports car with amazing history. Inspired by Jaguar XJ 13, Invicta, however, is an absolutely rare piece with its special shape. The bodywork is Kevlar panels on a very substantial chassis, finished in red. The interior is black.

The car is equipped with a central engine, Jaguar V12 and a manual 5-speed transmission, developing 490hp and a top speed of 300 km/h. Some still regard Tredecim as the most beautiful sports-racing car ever built, even if it never proceeded beyond a single car. Worldwide this model exists only in one exemplar.

Today it belongs to Hans Kleissl, a private collector and a renowned classic car professional from Germany. Hans Kleissl is the owner of HK-Engineering, an old-timer restoration company that works solely with exclusively valuable Mercedes Benz 300SL. Kleissl’s rich experience in the old-timer industry combined with his passion for unique cars led him to purchase “the only one” Tredecim.


a heritage spanning centuries

Invicta was a British automobile manufacturer. The brand has been available intermittently through successive decades. There were earlier but unconnected Invicta companies which made cars in Finchely, London from 1900 to 1905 and Leamington, Warwickshire, England from 1913-1914. There was also an Invicta in Turin, Italy in 1906. In addition, the name was also used on the Buick Invicta from 1959 to 1963.

Doom and resurrection

Tredecim was presented on a car show in 1984. It is the one and only product of Invicta Company that existed from 1980 until 1984. Still in the process of building the car, the company Invicta had to close due to the lack of money caused by this project. The prototype was sold to Forward Engineering, where Invicta’s main engineer, Ron Beaty, finished his work. Former Senior Development Engineer at Jaguar Cars and Chairman of the Jaguar Specialist Association, Ron Beaty founded Forward Engineering in 1957. While working for Jaguar, Beaty was in the “experimental team” of the V12 and made his way up to being one of all-time greats at work with V12. Forward Engineering has mostly specialized in the development, assembly, testing and installation of Jaguar motors for high performance sports cars.

Made with talent and passion

In his spare time, Beaty built single seater Daimler and Cooper-Buick hill climb cars. In addition, the talented engineer was also working with motor racing boats. Beaty built an engine for “Miss Windermere” boat, which broke two world water speed records. Keeping in mind Beaty’s incredible technical talent and passion for V12 motors, Invicta hired him to lead the building of Tredecim. The fact that after the company went bankrupt, Beaty was still eager to finish the work, under his own company’s name, is just another proof of Tredecim’s uniqueness and beauty.

Technical data

packed with power

Tredecim has Jaguar technics of 1984: standard gearbox and engine. For the production Jaguars units of that time were used, 5.3 V12 motor was bored out to 5.7, six Weber carburetors were installed. That resulted in horsepower 490 and maximum speed of 300km/h due to the five-speed ZF transmission. The body was built separately and was made of Kevlar, which makes Invicta XJ 13 one of the first cars to use the body of such material.
XJ 13
Year of production
Body type
Registration Number
Chassis Number
Engine Number
Targa Prototype
Number of doors
Number of seats
Engine position
Drive wheel
Number of cylinders
Max power [kW/HP]
360 / 490
Max speed
300 km/h
5706 ccm


More Invicta to discover

Copy of the original Invicta Owners Handbook

Download Handbook

Copy of an article from Jaguar Drivers June 1984 issue

Download Article