WhyFi

With chunkier, heavier tires in general, yes.

Last year, I had to send one of my road wheels off for repair so I threw on the gravel wheels (heavier wheels with 35mm G-One Allrounds - a reasonably fast rolling tire on pavement). They were on for a couple weeks, for both solo and group rides - very noticeable difference. I think that a large part of if it for me is the more ponderous feeling when out of the saddle - those heavier wheels really resist changing orientation, so the bike swaying side to side under me feels like a lot more work. To a lesser extent, in-the-saddle climbing efforts feel less smooth, like there's a slow-down between each down-stroke. Regardless, my climbing relative to my group ride peers was definitely impacted and, even solo, it just felt like more work, though teasing that out of the numbers isn't always easy.