Toyota Motor Sales (TMS), USA, Inc. announced that the general public has selected ‘Prii’ as the preferred plural term for Prius.

The Prius Goes Plural voting campaign was launched on January 10 at the North American International Auto Show in Detroitand challenged the public to help the automaker determine the plural nomenclature of Prius. The campaign coincided with the world premiere of the Toyota Prius family of vehicles. With 25 percent of the votes, Prii becomes the word not only endorsed by the public who chose it, but also as the term recognized by Toyota. As such, Dictionary.com has updated its entry for the word ‘Prius’ to reflect this.

Toyota unveiled the winning word at the Chicago Auto Show on February 20. After the more than 1.8 million votes were cast during the course of the six-week campaign, Prii beat out its four competitors: Prius, Priuses, Prium and Prien. Prius came in at a close second with 24 percent of the votes.

The plural of Prius has sparked debates since the launch of the vehicle 10 years ago. Now that the Prius family has grown, Toyota asked its customers and fans to help the company decide on a term to describe the plural of Prius vehicles, thus answering the decade-long question—what do you call more than one Prius? Online voting modules enabled the public to vote for their preferred plural of Prius as well as view real-time polling data.

With the expansion of the Prius family to include the Prius Plug-in Hybrid vehicle (PHV), Prius v and Prius c concept, Toyota hopes to further increase acceptance of the Prius brand by offering a wider selection of vehicles that each maintain Prius’ core values of high fuel economy, low emissions, proven gas-electric hybrid technology and environmental stewardship.