While the word “speed” indeed is “fart” in Norwegian, the movie “Speed” was released as “Speed” in Norway.
The poster is photoshoped, as one easily can tell by the premiere date in the bottom of the poster. The date “June 10” would’ve been written as “10. juni” in Norway.
Today, most movies not primarily marketed for children are released with their English titles in Norway. And back when the movies were translated to Norwegian, the titles were often not direct translations. In fact, the Norwegian Wikipedia-article for Speed makes an interesting claim about the the 1975 Japanese movie Speed was based on. While known in Japan as “Shinkansen daibakuha”, and as “The Bullet Train” in English speaking countries, the article claims that the Norwegian title was “Expressen er lastet med… dynamitt!”, directly translated as “The Express is loaded with… dynamite!”. I can’t find any sources to support this claim, but it does follow the norm of translated titles of the time.
Other translated Norwegian film titles include “Airplane!” as “Hjelp, vi flyr!” (Help, we are flying!), “Die Hard” as “Aksjon skyskraper” (Operation Skyscraper), and “Deliverance” as “Piknik med døden” (Picnic with Death).
They had the golden opportunity to name it “Aksjon flyplass” (Operation Airport), but went with Die Hard 2. But they returned (without a vengance) for the third Die Hard, which they named “Die Hard i New York” (Die Hard in New York). Similar to how “You Only Live Twice” was titled “James Bond i Japan” in Norway.