I understand that around 20% of the energy while cycling is lost by the deformation of the wheels. I also understand that in smooth and dry roads people use plain tires (no tread pattern) as these tires will get more contact area with the ground, therefore needing less deformation in order to equilibrate the forces (with P= F/A).
Now based on that, I was wondering if there is any estimate on much gravel bike tires (with some light tread pattern) might contribute to the loss of energy compared with road bike tires (plain) for the same conditions (dry, plain and smooth road). Is the difference going to be substantial and noticeable, or just a small percentage barely noticeable in efficiency? or more generally, is there any study quantifying the loss of efficiency as the tread pattern gets more and more predominant?
In principle I would expect that if the tread is close to "plain" but with some light pattern it shouldn't affect strongly the performance, but I am not sure if this is correct.
I am an amateur cyclist, and I will use my future bike mainly on the road, with a 5 to 10% gravel, so I need to make a decision based on this.