Originally Posted by
nrsmd
All things being equal.
The amount of speed increase will still depend on those things even if they're held equal across the two cases.
If you're talking about rolling resistance
per-tire, and we spitball a bike+rider with a CdA of .32 previously doing 20mph on level ground, you'd see somewhere in the neighborhood of a .8mph increase in speed at the same power.
Is there a speed increase that is measurable?
Yes, if your measurement is precise enough.