Allison and Chinese manufacturer, Zhongtong Bus, have collaborated to deliver 211 compressed natural gas (CNG) city vehicles equipped with the supplier’s T 270 transmissions with retarder to Armenian capital, Yerevan.

Yerevan sought a bus suitable for its hot summers, cold winters and narrow downtown roads and decided natural gas buses were best in the intensely populated metropolis.

The Zhongtong bus is powered by a 200 hp Weichai CNG Euro V engine and an Allison T 270 fully automatic transmission, with gross input torque of 900 Nm. The transmission has six forward speeds, one reverse and an integral retarder, which extends the life of the brakes and lowers maintenance costs.

“Allison’s fully automatic transmission has Allison’s patented Continuous Power Technology, which delivers shifts providing passenger comfort,” said Zhongtong Bus North China director, Zhang Zhengwei.

“Its torque converter technology multiplies engine torque to significantly improve startability and launch, resulting in higher operational productivity, which maximises the benefits of a natural gas engine.”

While a manual or automated manual transmission (AMT) loses power with every shift, Allison maintains its fully automatic transmission increases power and accelerated speed, achieving better fuel economy and fewer pollutant emissions.

As with all Allison fully automatic transmissions, the Allison T 270 transmission features Allison’s 5th Generation Electronic Controls. Allison fully automatics require only periodic oil and filter changes.

“The partnership between Zhongtong and Allison began in 2007 and the two sides have established a sustainable relationship for more than a decade,” added Allison Transmission China GM, David Wu.

“Allison is the world’s largest manufacturer of fully automatic transmissions for commercial vehicles, with a large global sales and service network.

“We will continue to provide high quality products and services to Zhongtong.”