I am sure it is a measurement "in smidgeons" concering overall "performance" of the Pirel, Fires or Michel...just don't (please) do what was mentioned herein some months back by someone in, I believe, USA...purchasing no-name china-junk for a Fulvia... because of the price.
I have always been partial to Pirelli "performance tires"; since they were (perhaps still are) 1st choice of many "sporty-car manufacturers" & generally rate high in "neutral-testing"...as Mich; Yoko & Conto also do...+ perhaps others I can't list now...because only the above 4 name pop in mind as being 'leading candidates'.
For wat is worth....Conti seems to always be 1 of the top brands...be it 14, 15, 16 or larger-sizes; leading me to believe that they only produce "top-tires".
I do not have Conti on any of my cars though...since they are so dern-expensive, even in Germany...where they are produced !!; but they also have a "private-label brand (supposedly the same tires at 1/2 price ???) that my tire shop recommends for "everyday cars"; they have been fine on our company vans & I can (oh help) half-way live / cry over the price

I remember the days when my tire-shop (same guys for 35 yrs !!!; my ...they got so old !!!) used to saved "good used wheels/tires for me...usually when some crazy-person traded 1/2 fat wheels/tires for 1/1 fat wheels & tires after welding on fender flares to a ...for example.. BMW 2002, Opel Manta:) etc.........ah, what times they were. I could even afford fuel back then !