Why do American semi-trucks (18 wheelers etc) exclusively use inline 6-cylinder engines, no matter if it’s a Mack, Detroit Diesel, Cummins, or Volvo-built engine?

Question

I get why they are diesel, but why are they all of the inline 6-cylinder configuration? Why not V6 or straight 8 or freakin huge inline 4-cylinders?

In: 715

Answer 1

Plenty of big V8 diesel trucks still operating here in Australia, but then we have road trains not just a tractor trailer with one trailer, ours have up to three trailers so they need the extra power to pull all that weight.