The GMC Syclone is a high-performance version of the GMC Sonoma pickup truck. Produced in 1991 by GMC, the Syclone spawned the similarly powered 1992-1993 GMC Typhoon SUV. Another vehicle, the GMC Sonoma GT, offered less performance but was seen as a companion model.At the time it was introduced, the Syclone was the quickest stock pickup truck being produced in the world.