Originally Posted by
Bike Hermit
Take a look at
this Schwalbe website article about tires and rolling resistance. In order to get less rolling resistance out of a skinny tire it needs to be inflated to a higher psi. resulting in a rougher ride. The spring 2013 issue of Bicycle Quarterly is devoted to tire performance and comes to some interesting conclusions about wide vs. skinny tires and rolling resistance.
What often confuses the issue is that skinny tires are generally built for speed where as fatter tires are built for flat protection and long life. This can make a huge difference in rolling resistance. So people come to the conclusion that fatter tires are slower than skinnier tires.