Some specs from Volvo website:
https://web.archive.org/web/20071022144322/http://volvo.com/bus/global/en-gb/products/city+buses/chassis/Volvo+B7R/specifications+E3.htm

Gross weight (GVW): 18 metric tonnes
Steering angle: 50 degrees
Output: D7E290, 213 kW, 1200Nm

The mod is too light and has too much power.

You can change the vehicle class to "bus" now