105% Rule - Tire Aerodynamics

Is anyone familiar with the 105% rule for tire aerodynamics? Here is an article: https://silca.cc/blogs/journal/part-5-tire-pressure-and-aerodynamics

I have the new Roval CLX 50 disc wheels. I am wondering if I should run the Conti 4000SII 28mm tires or stick with the 25mm.

I have no way of measuring the width of my wheels to see if they comply with the 105% Rule.

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Roval CLX 50s are 29.4mm external, so you are prob good if you want to run 28s, although they may measure a bit wider when miunyed. Spesh specs a 26c stock on bikes that come with that wheelset.

I would go with the 25. Contis measure wide, and tyres measure even more so on wide rims.