I had a V-10 Ford engine on a 2002 36' motor home which weighed 19K lbs. I can not remember the horse power, but it was a very good engine. I got 9 mpg on that motor home. I am not sure of the new Ford V-10 engines, but I am kind of surprised that some like them better even though they are getting less miles per gallon and that is because they have raised the horse power on the same block that used to be in the low 300 plus horse power to a max 300 plus engine.
That engine from Ford is bullet proof.