K280/310/320UD
The K280UD, K310UD and K320UD (known as KUD in internal records) is the double-deck citybus variant with a 8.9-litre DC9-18 5-cylinder 310 hp Euro IV compliant engine (hence the 310 in K310UD), or a 9.3-litre DC9-29 5-cylinder 280 hp Euro V compliant engine. The 'U' indicates the bus is designed for urban application, the 'D' points out the chassis is made for a double decker.
Read more about this topic: Scania K-series