I believe I read that this particular Mc Donald's kept their coffee hotter than the chain standard because a lot of customers picked up coffee on the way to work and bitched because it was cold when they got to work.
The chain told him to turn it down several times but every time he did the customers complained. But 158 deg will still take burn you pretty good.
I don't understand how keeping it hotter would save pennies....the other way 'round I should think.
Either way trying to hold a paper/foam cup of anything, between your legs, in a car, is dumb.