Originally Posted by
andychrist
Quite aside from the issues of rolling resistance and acceleration, there is yet another real world difference between wide and narrow tires: wind resistance. A narrower tire will slice through the air more easily than a wide one. Perhaps that advantage, in combination with the easier acceleration gained from the lowered mass, is greater than any that might be gained though optimized rolling resistance. Dunno, but this could at least partially explain the general preference for skinny tires among racers if such were the case. Anyway, you certainly wouldn't notice as much of a difference indoors, working out on rollers, as you would out on the road, against the wind.
My guess, since you aren't offering any real data either, is that going from a 23 mm diameter to 25 or 27 mm tire isn't going to change wind resistance by any significant amount. The increase in cross-sectional area is miniscule when compared to the remaining bike and human on it. In a peloton, I'll guarantee it makes absolutely no difference.
Rotational mass only matters under acceleration. So if you are doing a lot of climbing, heavier tires could pose a penalty. On the flats, not a chance.
Bottom line, it is all speculation without real data.