What is the difference between 25mm and 23mm tyres

25mm really is comfier than 23mm
Is there honestly much difference between 25mm and 23mm tyres? I’ve been using 23s for years in all weathers, even on tracks and canal banks, with no problems. On these tracks, you can manage as long as you don’t sit on the bike like a sack of spuds. Does 2mm make that much difference? I’m bemused by all the debate I keep coming across.

Leeflatz, via the Cycling UK forum

That 2mm extra width works out as 15% greater air volume inside the tyre. This means 25mm rubber gives a noticeably more comfortable ride on most surfaces than the 23mm equivalent at the same pressure.

Richard Hallett

Technical Cycle magazine