 The first two examples of the Mark IX were apparently delivered to the US with the 1100 cc Coventry Climax engine to compete in the 1955 running of the 12 Hours of Sebring race and were beaten by a Porsche Spyder.These cars were actually entered as Lotus Mark VIII models in the G class by Frank Miller of Larchmont, NY and by Bobby Burns and Norman J. Scott of Houston TX in, respectively, car numbers 78 and 79.The Lotus Works Team entered at least one Mark IX in the Le Mans 24 hour race in 1955, driven by Chapman, which may have been equipped with disc brakes.