2005 Z Touring

Front -225/45/18
Rear - 245/45/18

Michellin Sport

The rear two are brand new... the front two need to be replaced in the next 5000 miles...
That's where I started thinking it was time for new wheels...

I want a wider tire up front... So i thougth about moving the 245/45/18 to the front onto a new wheel, and buy new rear tires, something like a 275/45/18.
I browsed throught about 15 of the 20 pages on the "18 inch wheels" thread and it looks like some people are running 245/45 up front with 275/45 in the rear...

My question is the sizing of the wheels... Do i go with a 18x9 for the front? what about the rear? And offset...?
The car is not lowered.... Most I would ever go would be an inch...

So I just need to know if i can move my new 245/45's to the front onto a 18x9 and buy 18x9.5 and new 275/45/18 tires for the rear??? And what offset is advised...

Thanks,
I'm ready to buy some stuff just hesitant due to the local tire guy's swearing it's not advisable, and to stick to stock sizes (BS)...

 

Generally a 3 percent speedometer error is acceptable. 3.8 MPH is not.

 

Now this could be the captain talking seeing how it's almost 1 AM... but what does that have to do with asking about tire sizes... I'm not looking to change the height of the tire.. just the width and rim size...

 

Well the tire sizes you posted increase the overall diameter. the proper size is listed all over this section , proper wheel width and offset is posted all over this section. Just look around a little.

 

Isnt a 245/45/18 the same height as a 275/45/18, just wider? Or did I completely misunderstand what I've throught for the past several years of my life...

 

Oh but you have altered tire height which alters speedometer reading.

 

Width x aspect ratio = sidewall height.

245 mm x .45 = 110.25 mm

275 mm x .45 = 123.75 mm