when i went from 23s to 25s I didn't notice and speed difference either in city or on the road. I noticed some speed decrease when doing group rides because it took more effort to close on the back of someones wheel when the slinky effect started on a long paceline. The biggest difference was from a stop to 20 MPH. But 28s were more comfortable around town and for a city bike better suited to the cracks and bumps I encountered. However my solution to snow and ice is different than some. I would move.