 Complete the following phrase:  In , Arnoux took his first two Formula One victories, the first being at Interlagos circuit in Brazil. His second win came in the very next race at the Kyalami circuit in South Africa, where the thinner air at high altitude gave the turbocharged Renault RE20 have a power advantage over its mostly Cosworth-powered rivals. Following this race, Arnoux was leading the World Championship for the first time. He would not lose the championship lead until Round 6 in Monaco. The season though was punctuated by unreliability from the turbocharged Renault V6 engine. The unit was powerful, producing approximately to be on par with Ferrari and considerably more powerful than the Ford DFV, but fragile, and the Renaults also lacked ground effects. Although he would later finish second in the 