Try to search for "truck" on the whole forum, probaly the type of racing that have been suggested the most. Though I mentioned too in another thread, but that was "What kinda racing would you like to see in lfs". Try to check that thread out.
He might want to rethink, a modern day diesel can be a lot faster than an equivalent petrol engine (more torque for the same engine size and power) and it`s a lot more economical two. (As an example: The Audi Q7 V12 TDi - and i hate Audis.)
no not pickup trucks (would be nice though) would be fun to get a UF1 in the middle of the two trucks. and i think they would have to rethink the whole sim for it. I.E have pit stops like 3 times a lap (they must not get good MPG)