BEIJING–(BUSINESS WIRE)–Allison Transmission, a leading designer and manufacturer of conventional and electrified vehicle propulsion solutions and the largest global manufacturer of medium- and heavy-duty fully automatic transmissions for commercial and defense vehicles, is pleased to announce a partnership with leading Chinese bus manufacturer Zhongtong Bus Holding Co., Ltd. to deliver 211 compressed natural gas (CNG) city buses equipped with Allison T270R transmissions to Yerevan, the capit