Give me a good reason why you call the X5 a "truck".

[StumpyPete]

In UK it can be any of 4WD, 4x4, Chelsea Tractor, or indeed Car. The UK Driver and Vehicle Licensing Agency (government) class it as a car.

Hardly anyone uses the term SUV. Only BMW salesmen use SAV, and NO-ONE would ever call it a truck.

But then again truck is hardly used at all. Heavy Goods Vehicles are HGVs or Lorries.

If I was being pedantic, I would argue that for something to be a truck then its primary purpose would be for carrying goods and not people. But I recognise that the definition is somewhat vague in today's society. Somewhere along the lines of the last century (the appropriate etymology of truck is early 20c) function and size became confused.

Online Etymology Dictionary