The Rennmax name was applied to a series of open wheel racing cars and sports racing cars constructed by Rennmax Engineering in Sydney, Australia between 1962 and 1978. Rennmax Engineering was established by Bob Britton in 1961, its name derived from the German word "Renn", meaning race and the abbreviation "max", for maximum.
Although Rennmax cars are often referred to by model designations such as BN2, BN3 etc., Britton claimed that the origins of these were unknown to him and in practice he did not even stamp chassis numbers on his creations. The following list utilises these unofficial model designations and also includes models which were built by Rennmax Engineering but raced under names other than Rennmax.
The first Rennmax chassis, built for Noel Hall in 1962, utilised numerous components from Hall's Cooper, including a 2.2-litre Coventry Climax engine.
The Rennmax BN1 was a single seater racing car incorporating concepts from the Lotus 20 & Lotus 22 designs. At least 6 examples were built circa 1962-1964.
The Rennmax Vee was a Formula Vee racing car produced in series for Greg Cusack and Bruce Burr. Nine cars were built during 1965-66. The cars were originally referred to as CBs but each example was later renamed to "Rennmax".
The Mildren Maserati was a sports racing car built for Alec Mildren in 1965. It was constructed in the style of the Lotus 23, utilised various components from a Cooper T51 and was powered by a 2.9-litre Maserati Type 61 engine.
A series of replica Lotus 23 sports racing cars were constructed in the mid 1960s.
The Matich SR3 sports racing cars were constructed by Rennmax Engineering for Frank Matich. Bob Britton then accompanied Matich to the United States when he competed in the 1967 Can-Am season.