The Type 89 medium tank I-Go (八九式中戦車　イ号, Hachikyū-shiki chū-sensha I-gō^?) was a medium tank used by the Imperial Japanese Army from 1932 to 1942 in combat operations of the Second Sino-Japanese War, at Khalkhin Gol against the Soviet Union, and in the Second World War. The Type 89B model was the world's first mass produced diesel engine tank. The tank was armed with a short-barrel 57 mm cannon for knocking out pillboxes and masonry fortifications, and proved effective in campaigns in Manchuria and China, as the Chinese National Revolutionary Army had only three tank battalions to oppose them, which consisted primarily of Vickers export models, German Panzer Is, and Italian CV33 tankettes. The Type 89 was a 1920s design medium tank, built to support the infantry, and thus lacked the armor or armament of 1940s generation allied armor; and was regarded as obsolete by the time of the battles of Khalkhin Gol, against the Soviet Union, in 1939. The code designation "I-Go" comes from the katakana letter [イ] for “first” and the kanji [号] for “number”. The designation is sometimes transliterated “Yi-Go”

I-GO is a Chicago-based not-for-profit car sharing organization. I-GO was established in 2002 by the Center for Neighborhood Technology, is an independent 501(c)(3) non-profit organization dedicated to creating and implementing new strategies that make urban communities more livable and environmentally sustainable.

I-GO’s mission is to reduce car ownership rates, decrease transportation costs, reduce urban congestion and improve air quality in Chicago. Since its inception, I-GO has worked to catalyze a set of transportation innovations that make it feasible and desirable for Chicago residents to get around conveniently and economically without having to own a car and, at the same time, reduce vehicle miles traveled and greenhouse gas emissions. By contributing to the environmental improvement of the Chicago area and the decrease in expenses for residents, I-GO's triple bottom line impact provides a significant social return on investment.

I-GO currently has cars located in approximately 30 Chicago neighborhoods. I-GO members can reserve a vehicle online or by calling I-GO's customer service. Members can also create and modify their reservations using smart phones. Once a reservation has been created, the member can access the reserved car using a member card, use the car and then return it to the same location. Members pay a one-time fee to join, an annual renewal fee, and are then billed by the hour for their use of I-GO cars; specific rates vary depending on type of plan. Gas and insurance are both included in I-GO's rates. As of June 2009, I-GO had more than 12,000 members and 185 cars available for use.