HELLO.

I have got a question i can't figure out.


My BMW X5 4.6 IS has now rims of this size
Front:
BMW 275/40 R20
6 7535 16?
E9 1/2J
X20EH2?
IS45?

REAR:
BMW 315/40 R20
6 7535 17?
E10 1/2
IS30?

I HAVE ALSO GOT 4 TIRES OF SIZE 275/40 R 20


????? mY QUESTION IS: WHAT ARE THESE OBRIVIATIONS MARKED BY QUESTION SIGN STAND FOR?????
AND WILL THE SIZE LISTED ABOVE PERFECTLY FIT THE SIZE OF TIRES WITH 275/40 R20 TO CONSIDER THE RIMS ARE A LITTLE BIT DIFFERENT IN WIDTH???

AND ONE MORE WHAT IS THE DIFFERENC IN IS 45 AND IS 30 REGARDING RIMS? AMD WILL FOR EXAMPLE RIMS OF FRONT SIZE FIT THE REAR?