Hello; Cabovers are common over in Europe because their roads have tight corners which are too hard for conventional cabs to handle. Over here in the USA, cabovers are very rare nowadays. Back in the 1980s and down, cabovers were common and popular here in the USA, then safety and increased length limit are what decreased the number of them. Sort of, In Europe the total length of the truck and trailer is regulated which is why you want the Cabovers to maximize cargo space. Other difference is a higher max weight, In Sweden its 60 tons (120 000 pounds) and in Finland its 152 000 pounds. This is one of the reason for the more powerful engines found in the top line Swedish models. Kenworth, Peterbilt, Mercury, International-Harvester- Mcleod (or IH) these are the trucks that are made for heavy duty trucks in the USA long time back, and these are one of the best in the world. These trucks are all semi-tractors. Semi-tractors have a high power diesel engine of over 300 housepowers.