I have query here regarding the tyre replacement. 1. I have found side wall crack in one tyre should i change it or use it as spare tyre where others are running fine,i think it will run at-least 20K kms. pic can be found in this thread http://www.teamfiat.com/threads/minor-issues-tyres-alloys.662/page-98 2. If change is required can i go for 185/70 R14 for only one tyre and others will be running on OEM 165/80 R14 any issue will be there by this kind of setup in running or issue during warranty claim. 3.Can i go for other brand for this single tyre as my current stocks are JK Tyres.