There’s plenty of talk in the industry about electric trucks and the numbers being added to large fleets on an almost daily basis, so much so that it feels that gas trucks have almost been forgotten.

Trucks powered by natural gas, and especially bio-gas, are generally considered to be less polluting than their diesel cousins in terms of particulate and CO2 emissions.

A byproduct of the huge amounts of the waste we produce in the UK is bio-methane. If this is vented to the air, it represents a huge potential to add to greenhouse gas emissions. For this reason, it needs to be burnt. Rather than simply burning the bio-methane at source, it can be used to power a truck – saving the burning of a fossil fuel – diesel.

So, the gas is going to be burnt anyway, so why not take advantage of the energy it contains?

Not everyone agrees. Environment group, Transport and Environment say that gas trucks are as bad – of maybe even worse than diesel trucks.

Rather than debate the facts here, let’s take a look at the 6×2 tractor unit availability.

Iveco S-Way 6x2 CNG
The Guest Trucks’ S-Way conversion stretches the chassis to 4 metres, adds a lightweight Iveco mini mid-lift axle using all Iveco parts and in collaboration with Iveco

Gas Storage on-Vehicle

Truck makers need to store loads of gas on a tractor unit to give the truck sufficient range to be marketable in the UK.  To achieve this, the gas is either compressed (CNG) or liquified (LNG).

CNG tanks will take up more room on the truck whilst LNG is a lot more difficult to refuel – both from a driver viewpoint and a refuelling infrastructure situation.

Basically, CNG is better operationally, but you’ll need large tanks.

As any tractor unit operator well knows, there’s not a lot of room on a 6×2 tractor unit chassis for large tanks of any description, let alone the number required to store sufficient CNG.

It is much easier to achieve this on a 4×2 tractor unit, but this loses the benefit of the additional four tonne gross train weight (GTW) allowance enjoyed by UK truck operators (although not by our continental cousins).

As a result, 4×2 CNG tractor units are available aplenty, whilst 6×2 tractor units tend to be LNG powered as the denser fuel means smaller tanks that will fit on the chassis.

Time to answer the question, Can I Buy a new 6×2 CNG Tractor Unit?

The short answer is yes, but this could change over time, you could used to buy a 6×2 CNG Iveco Stralis, but the S-Way is not available as a 6×2 CNG versions out of the factory.

DAF, MAN, Renault and Mercedes have no CNG tractor unit offerings in the UK, so you are immediately restricted to Scania, Volvo or Iveco for a gas tractor unit.

Volvo offer a 6×2 gas tractor unit, but only in LNG form with a lightweight pusher axle or tag axle.

This mean, as of January 2025, there are only two available options for a 6×2 CNG tractor unit.

Scania 6×2 CNG Tractor Unit

Revealed in June 2024 is Scania’s R460 6×2*4 CNG rear steer tag axle tractor unit The manufacturer has taken advantage of the revised dimensions regulation to fit a revised bumper and extend the wheelbase. This means that larger tanks could be installed on the side of the chassis rails plus a further pair behind the cab. Scania claims a range of 600kms for the truck. The Scania uses the 200bar refuelling option.

scania-6x2-cng-truck
Scania claims a range of 600kms for the truck which uses the 200bar refuelling option

Iveco S-Way 6×2 CNG Conversion

Also revealed in September 2024 is a dealer/manufacturer conversion of a 4×2 Iveco S-Way CNG to a lightweight mid lift 6×2 44 tonne tractor unit carried out by Iveco dealer Guest Trucks and Astra Vehicle Technologies. Another Iveco dealer South West Truck & Van also have a 6×2 S-Way conversion available.

The conversion stretches the chassis to 4 metres, adds a lightweight Iveco mini mid-lift axle using all Iveco parts and in collaboration with Iveco. The truck is capable of running at 44 tonnes and a minimum range of 300 miles between fills with a CNG storage solution that can utilise the UK’s ability to fill at 250bar

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