I have a pair of Michelin 19/57/15 wets in P2A compound, and looking to get 2 more, ive seen some same size but in P2G compound, whats the difference??
From Michelin info they say last letter refers to 'Evolution' but what does this mean? and would it make a differance to have a mixed set for a track day?

Tyre markings explained
Example:
24/64-18 P2E
24 : Tread band width (cm)
64 : Exterior diameter of the tyre (cm)
18 : Rim diameter (inches)
X : Radial tyre
TL : Tubeless tyre
P : Rain
2 : Compound stiffness
E : Evolution
S : Slick
P : Rain
Number (2, 5, 6, 7, 8, 9) : Compound stiffness
Letter (A, B, C, D, E, G) : Evolution