The B5LH is powered by Volvo's in-house parallel hybrid drive train that couple its I-SAM motor to a 5-litre D5-series diesel engine. The drive train is connected to the Volvo I-Shift automatic transmission that drives the rear axle. The whole drive train is mounted in-line at the left rear of the chassis, similar to the B7L. A lithium battery pack is mounted just behind the front left wheel, powering the I-SAM motor system.
The B5LH features stop-start system that allows its engine to cut off when the bus is stationary, and the battery is sufficiently charged. It is also capable to drive at full electric mode from standstill to up to 20 kph. In service, Volvo claims that the B5LH achieves 35% improvement on fuel consumption and reduces the emission of greenhouse gases, including carbon dioxide by an equivalent amount. In service data in London shows that the B5LH is demonstrating between 25 and 40% of fuel consumption improvement.
| Manufacturer | Volvo |
| Body and chassis | |
| Doors | Single door or Dual door vb |
| Floor type | Low floor |
| Powertrain | |
| Capacity | 90 Passengers |
| Transmission | Volvo I-Shift 12-speed auto |
| Dimensions | |
| Length | 10.5m (Early version: 10.4m) (Double-decker) |
| 18.0m (Articulated) | |
| Width | 2.55m |