Hello,

I ride 2008 G35x which is AWD.

I am thinking of increasing my rim size to 19" and with my choice of a certain rim set, I was told that the tire sizes will be:

245 40 19
275 35 19

Will this a problem for the AWD cars such as G35x?

How will the performance be affected?

Thanks,
Seoho

 

Assuming your stock size is 225/55-17, the following shows the range of sizes by overall diameter. The highlighted ones should be suitable from that perspective but may not fit both front and rear (see below).

225 50% 17 26.74 Stock Reference Size

245 35% 19 25.75
245 40% 19 26.72
245 45% 19 27.68
255 35% 19 26.03
255 40% 19 27.03
265 30% 19 25.26
265 35% 19 26.30
275 30% 19 25.50
275 35% 19 26.58
275 40% 19 27.66
285 40% 19 27.98
285 35% 19 26.85
285 30% 19 25.73

HOWEVER.... would caution you to stick with ONE SIZE at all four corners due to the AWD configuration. In case you didn't know (assuming lowest common denom), electronic AWD of most varieties (ATTESA ETS in your case) use wheel speed as one of the main determinants to decide how to split torque delivery F-R.

Deviating from specified tire sizing may (not definitely) alter how the AWD behaves on your car due to the different wheel speeds when deviating tire sizes (stagger front to rear).

The sizes you quote are close in overall diameter but even that minute deviation might lead you to issues. So, that said, would recommend you go with the 245/40-19 all the way around unless you can physically install the next suitable size up, 275/35-19 on both front AND rear. Not sure if the 275 fits up front on your particular car though.

Again, not absolute but I wouldn't take chances. The policy of the shop I ran a few years ago was to NEVER advise staggered setups for tire/wheel purchases AND if someone just needed a single new tire, we would NOT sell them a single - all for this reason.

 

Considering if you got a flat tire and brought your car to a repair shop for 1 new tire they would tell you that you need all 4 new tires so they are the same tread and size. You will not want to run anything but all 4 of the same tire sizes unless you want some major issues.