I mean I can turn in the same time and speeds on a 40c MSO that I can the 28c GP4000sII on the same 20 mile loop with the same bike and same wheels.
the differences will be in the 'POWER' it took to do that. and that 'power' difference starts adding up fast when you turn 5 miles into 20, and 20 to 40, and 40 to 80.
even more so if you are cruising at 23-25. Did you have a tail wind? were you drafting? (group ride tells me you were most likely drafting) too many variables. 1 ride doesn't mean that the tires don't have a difference.