I went to get an oil change and firestone told me i need new rear tires.

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left front Outer is 7 Inner is 5
right front Outer is 7 Inner is 5
right rear Outer is 5 Inner is 2
left rear Outer is 5 Inner is 1

The guy said the rear tires need to be replaced because 2 is dangerous and 1 is illegal in the state of hawaii. I just bought these wheels used and i dont wanna be buying new tires every 5k miles. Its way too expensive since my rears are like 10 1/2 inchs wide.

What do i need to do??I understand this is negative camber but Im a noob with this ..Do i need a camber kit?? Rear arms?? Nothing i can do??? Please let me know before i go waste money on new tires to have the inner part wear away again.

Im on Tein S-techs with 19's

You need to install a rear camber kit. Make sure it is installed correctly. You have to elongate holes when installing the kit. After that, get an alignment and you should be fine.

what are your current alignment specs. You can have the tires flipped so that the inner tread is now on the outside to prolong the life a little longer. Sounds like a you need a rear camber kit though. The SPC(eibach, ichiba) kits with toe bolts are the most cost effective choices for the rear camber kit.

Here's a DIY to get a better idea of what youre going to need....

http://turboneticsownersclub.com/tur...oltinstall.pdf

I havent had an alignment. Should i do that first?

I would save the time/money and just purchase and install a SPC rear camber kit before the alignment. I'm 99% sure you'll need one. Do you have 350z s-techs or g35 s-techs