My fixie came with Bontrager 28mm tires that actually measured about 26 and I found them a little narrow for my commuting route so I put on Vittoria Rando 37mm tires that actually measure about 32 and I like them a lot better. I don't notice the rolling resistance so much as the extra weight to accelerate when I'm just pushing off, but they inspire confidence on the sections of gravel and dirt that I have to go through.