Between the end of 1953 and the first months of 1954, Lancia, having noted that the power of the D24 3,284 cc was insufficient to face the competition, began developing a larger displacement engine, the D25 3,749.69 cc, which mounted on a Lancia D24, made its debut without much success on June 27, 1954, at the Grand Prix of Porto. The V6 produced 300 hp (224 kW), giving the car a top speed of 290 km/h (180 mph).[1]
In Lancia's initial intentions, it is to develop a more competitive version of the D24, not only with a more powerful engine but also in other technical aspects of the car; however, development does not proceed as initially planned and only after a few months it stops. Unfortunately, Lancia's financial difficulties begin to become evident in the second half of 1954 and compromise investments not only in the development of the car but also in the continuation of Lancia's motorsport racing.[2]
Lancia Aurelia second series sales are proceeding slowly, while those of the more recent Lancia Appia are not reaching the expected numbers of sales, an obvious sign that the victories and performances of the Lancia D23 and Lancia D24 have not helped to increase the sales volumes of the production cars, and Gianni Lancia, already dealing with the issues related to the Lancia D50[3] Formula One car, begins to seriously consider the possibility of abandoning sports car racing and, as a first step in that direction, reduced the considerable investments that the development of the Lancia D25 seems to require. However, the Lancia D25 raced on September 11, 1954 at the RAC Tourist Trophy. Both Lancia D25 in the race are forced to retire. The D25 was very similar to the previous D24, the differences besides the engine also concerned the chassis, modifications made necessary to accommodate the new larger and more powerful engine, furthermore the suspensions were also improved and the wheelbase also changed: of the three cars initially assembled, two had an extended wheelbase (245 cm instead of 240) and one, on the contrary, a shortened wheelbase (230 cm). After the dispute of the Tourist Trophy, the development of the D25 comes to a stop: a week after the poor performances seen in the English race, a Lancia D25 is entrusted to Eugenio Castellotti to compete in the Bologna-Raticosa hill climb in Italy, a race later won. However, some believe that a Lancia D24 was used instead of the more powerful Lancia D25. The Eugenio Castellotti's #234 Lancia Spider was registered TO 158156. After that race won, the Lancia D25 is no longer used in racing by Lancia. On October 18, 1954, Lancia announced its withdrawal from motorsports to focus its now scarce financial resources exclusively on Formula One, in order to gain better international visibility and increase its poor sales. Despite Lancia's now well-known financial difficulties in 1955, Gianni Lancia was persuaded to build a Lancia D25 with a different bodywork – again by Pininfarina – featuring a lower and wider front grille, at the request of Alberto Ascari, who had wanted to participate in the Carrera Panamericana at the end of 1955. But Alberto Ascari's death on May 26, 1955 marked the inexorable and definitive end of the D25, which, almost complete, was somehow finished and immediately relegated to the Lancia Museum.[1][2] Ascari's death marks the collapse of Gianni Lancia's certainties, who will first close all Lancia's motorsport racing and a year later, in June 1956, will leave forever the presidency of Lancia and will sell the Lancia company to Carlo Pesenti of Italcementi.[4][5][6][7]
