Widely known as Lancia Stratos, the HF stands for High Fidelity. It started a new era in rallying as it was the first car designed from scratch for competition.
The Lancia Stratos was, above all, a rally homologation special, designed by Marcello Gandini, head designer at Bertone. The unique, stubby wedge styling gave the Stratos a tough, almost menacing, personality, and the few examples seen on the road have always looked dramatic.
For racing, the engine was tuned up to 280 hp (209 kW) and even to 560 hp (418 kW) with a single KKK turbocharger.

Turbocharged versions were only allowed to compete in Group 5 and were never as reliable as their naturally aspirated counterparts.
The Stratos won three World Rally Championships and became one of the most desirable, if least practical, sports coupes of all time. The car won the 1974, 1975 and 1976 championships in the hands of Sandro Munari, and might have gone on to win more had not internal politics within the Fiat group placed rallying responsibility on the Fiat 131 Abarths. The Stratos won the Monte Carlo Rally with the private Chardonnet Team as late as 1979.
Only 492 of these cars were ever built