In For The Long Haul

Volvo is making a comeback to the gas-powered truck market, but does the driving performance compare favourably to its diesel offerings?

Volvo has joined the ever-expanding club of truck manufacturers producing factory-built gas-powered long-haul trucks. Unlike Iveco and Scania, which have opted for Otto cycle spark ignition engines, Volvo has gone for compression ignition, citing its 15-20% better thermal efficiency, and liquefied natural gas (LNG), which has a much greater energy density than compressed natural gas (CNG).

This does mean that the Volvo is a dual-fuel device, requiring the injection of a small (5-10%) shot of diesel to ignite the gas instead of a spark plug. As much of its technology comes from Volvo’s current Euro-6 diesel engines, it needs the same SCR after-treatment, although it dispenses with EGR. Volvo claims a 20% cut in CO2 using fossil-sourced natural gas and a 100% reduction of overall CO2 impact when using bio-fuel.

Up to 1000km

With the largest tank fitted, the Volvos are capable of a range up to 1000km. Of particular interest to UK operators, this includes a 6x2 tractor, but so far only in a tag-axle configuration. With the medium tank, which can be fitted to pusher-axle 6x2s, the maximum range is the same as that of its rivals.

From the head gasket down, the G13C LNG is largely based on the familiar 12.8-litre D13K Euro-6, Step C, diesel engine. Available in 420hp and 460hp ratings, with 2100Nm and 2300Nm of torque respectively, it can be fitted to FM and FH models.

The key difference is a unique fuel injector that uses two concentric needles to supply fuel from two sources at the same time. The biggest visual difference externally is an extra hydraulic pump that powers the gas pump within the tank, raising supply pressure to 300bar. Although there are some added maintenance costs owing to a higher component count, service intervals are higher – at 100,000km – than the Otto cycle rivals.

Not a success