4.5-liter chassis employed an innovative, sophisticated, but unfamiliar, independent front suspension, being the recently introduced Dubonnet system, licensed to Delahaye by the inventor. Dubonnet's system was in use prior to the Delahaye, having been licensed to General Motors two years before, in 1933, as well as by Alfa-Romeo, Simca, and Vauxhall. After WW2, only Vauxhall and Delahaye retained the Dubonnet system. Others had moved on to the unequal-length A-arm system, pioneered by Cadillac head engineer Maurice Olly. The GMC system was licensed by Rolls-Royce, for its Phantom-111 and Wraith model, and it subsequent postwar Silver Dawn, Silver Wraith and Bentley Mk-6 models. Dubonnet systems proved problematic, unless fastidiously maintained. Oil-seal leaks caused seizures,and suspension collapses. Accidental damages were sustained by an undisclosed number of early cars in the 175/178/180 series. Parts failure reports doomed the new series to failure, irreparably damaging Delahaye's long respected reputation. The excessive weight of traditional hardwood body-frames clad in mild steel panelled, hand-hammered and welded coachwork, mounted atop these already heavy chassis adversely affected acceleration and speed, while compromising handling. French coachbuilders employed antiquated, traditional, building methods and common materials. They were almost universally oblivious to weight. Only Henri Chapron, and Olivier Lecanu-Deschamp, were familiar with forming and welding aluminum. Other French coachbuilders were creating their bodies with hand-hammered and welded steel sheets mechanically fastened over hardwood body-frames. Consequently, they were inordinately heavy, and contributed to mechanical failures experienced by an estimated dozen early purchasers. Broken suspension components resulted in Delahaye being obliged to buy back the offending cars, at considerable expense, to circumvent litigation, and negative publicity. The Type 175S racing-engines Delahaye developed for Charles Pozzi, and racing-team Ecurie Lutetia co-owner and French champion driver Eugene Chabaud, reportedly had a 9.1:1 compression ratio, which with three Stromberg dual-choke carburetors, delivered over 220 bhp. These two 4.5-litre displacement racecars were parallel in horsepower to three of the four Type 145 cars (48772, 48773, and 48775). The more highly-tuned number 48771, after Fernand Lacour's efforts, developed a recorded 244.8 horsepower. The Type 175S model had just two factory options: Rudge wire-spoked wheels; and three Solex 40AiP down-draft carburetors. Coachbuilders addressed everything else a customer desired or specified. The new 4.5-litre engine carried the "183" casting-code. The motors were built in two distinct forms. The initial engines were stamped: Type 1AL-183, as found in all six pre-production units known about by 1946; and, the two Type 175S