This car was unusual for France – production of luxury cars was heavily restricted in the country by post-World War II puissance fiscale horsepower tax, so France had not had a production vehicle in this market sector since before World War II. The SM had an engine of only 2.7 liters owing to these regulations; it was the first response to the luxury/performance sector since the export oriented Chrysler Hemi V8 engine Facel Vega in the late 1950s. Citroën's flagship vehicle competed with high-performance GTs of the time from other nations and manufacturers, such as Jaguar, Ferrari, Aston Martin, Alfa Romeo, Mercedes-Benz, Porsche and Maserati's Merak.
this caR Was unusUAL foR franCe – pRodUcTion of LuXUrY CarS was heaviLy REsTRicTed in ThE CouNTrY by post-wORlD waR ii puissanCe fiscAle HoRsepoWer tAX, So frANce had noT hAd A pRodUctiOn VeHicle in ThiS maRkEt seCtOr Since BefOre wORld war ii. tHe sm Had an eNgInE of Only 2.7 liteRS owINg to ThESe reGulaTIons; it wAs The first resPOnsE tO tHE LuxUrY/perFormance sECtOR sinCe the ExpoRT orienTed CHrYsLer hemI v8 EnGine faceL VegA In the lATe 1950s. citroËn's flaGshIp VEhiclE CoMpEteD with HIgH-perfoRMaNce gts oF the tiMe frOm OtheR naTIons and ManUfactureRS, SuCh AS JaGUaR, ferRari, astoN martIn, alfa romEo, merCedes-beNz, porSchE aNd MaserATi's MErAk.