Starbucks Tests New Size: 31-Ounce 'Trenta' Iced drinks available only in Phoenix and Tampa for now By Nick McMaster, Newser Staff Posted Mar 3, 2010 4:33 PM CST 14 comments Comments Customers place orders at a Starbucks Coffee in Indianapolis, Wednesday, Jan. 20, 2010. (AP Photo/Michael Conroy) (Newser) – Starbucks is offering a 31-ounce cup of iced coffee or tea in Phoenix and Tampa. The move is likely another step in the competition between McDonald's and Starbucks—McDonald's sells 32-ounce sweet teas in Southern markets, and recently started offering espresso. The new Starbucks size is called "Trenta." An iced coffee in that size costs $3.30 and an iced tea $2.60, Reuters reports.