Like cars, trucks are made with a variety of different purposes in mind. They’re a tool for a job.
In the same way you couldn’t service a car with a hammer and chisel, you couldn’t deliver beer to pubs on a 44 ton artic.
To get to pubs and clubs dray lorries have to be compact, because of this they can only carry about ten tons payload, so a single axle trailer is all that’s needed. More axles would just be extra weight and cost for no benefit.
The fuel tanker has a low cab because it’s lighter and therefore it can carry more payload.
The same with the small mid lift axle, it’s lighter than a full size one but still allows it to carry 44 ton. The weight on a tanker and tipper lorry is spread evenly so makes these a good option.
You wouldn’t see these small axles on a general Haulage vehicle because they offer less flexibility for overall weight distribution.
A full-size midlift axle can carry 8 tons a small one will only carry 4.4.
Hope that helps
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