[CapriRacer]

Originally Posted by Ernie Rogers

.....

Could the difference of-- .009 /.00878 = 1.025-- 2.5% in Crr
be detected with a wheel tire tester? Maybe just barely. Any thoughts from the real world experts here?

Ernie Rogers

Just an anecdote from the trenches:

I know a major vehicle manufacturer refused to accept a tire modification proposed by a major tire manufacturer because the RR increased 3%. That tells me that not only is 3% detectable and reliable, but it also is detectable in the EPA Fuel Economy Test.