Looking for wider rear tires on my 2012 GT premium. Currently have 245/45/19's all around. Will 275/45's work? Thanks.

 

Depends on wheel width. Go by tire manufacturers data specifications.

 

Which rims do you have?

 

According to TireRack, you'll need a rim width of 8.5-10.5" for a 275/45-19 tire.
The tire OD is 28.8", which if taller than your current tire, will change your rear end ratio.
Most likely mess up your speedometer too.
.

 

Thanks, guys

 

Based on the wheels it looks like you have, the tires will probably bulge a little bit, but should be ok. You are pushing it on the size though and I wouldn't go any larger than a 275 on an 8.5" wheel.

 

I run 275's on the stock brembo 19 x 9" wheels at all four corners without any issue. I wouldn't go any wider on the 9" wide wheels and am considering buying a set of 19 x 9.5" wheels. You can fit wider on the rear if you have the right wheels (width and offset).

 

Actually you should probably run a 275/40 19, pretty close to the same height as the 245's you have on now.

 

The 275 40 19 is almost the same height as the stock 245's, but fills the wheel wells out nicely.