Though I believe that science and math would prove me wrong, the smaller the amount of tire touching the pavement, the lower the co-efficient of friction, reducing drag all equaling faster. To that add that larger tires and inner tubes add weight and reducing weight seem to carry a lot of weight with professional riders. Again, this seems logical. Also, the additional bigger tire and inner tube weight would negatively impact the feel of the bike. Prove this to yourself, if you wish. Spin a wheel, holding the axle ends, with no tire and tube installed and, while spinning, tip the wheel from side to side. Notice the resistance you feel when doing so. Repeat the same test with a wheel fitted with inflated tire and inner tube. Notice how much more resistance you feel now, compared with the unclad wheel.

Anyway, just an opinion. Also, I do like the appearance of skinny tires, such as those on my Atala...




These NOS (emphasis on old) that I bought from a local bike shop shredded themselves in short order the first year I rode them in Jamaica...


But for comfort sake, these tires, fitted to my Jamaica Bianchi(last picture), are the destroyer of any skinny and/or tubular tire myths that once formed my opinion. I will go with more air and less glue these days...