Mazda 6 GH AM Wheel Upgrade Compatibility
 

Hi. New member and thanks in advance for any help.
I've a 2009 Mazda 6 GH Hatch that has served us really well after owning a Mazda 6 GG Luxury Sport previously. We are looking to hand the car down to my son who will be driving soon and given the tyres are due I was hoping to upgrade the wheels at the same time.
The car currently runs the standard 17 x 7 55 Offset on 215/50's. I'm looking at the WRX STI 2015 vintage rims which are the same 5 x 114.3 and 55 Offset. The rims are a 17 x 8 running on 235/45's. The circumference difference is minimal hence no real issue to the speedo readings so my main concern is around any potential clearance issues with the wheel being an inch wider. Given the offset is the same, I believe the wheel will extend 12.7mm further on both sides. I don't think going out half an inch is an issue but concerned about the clearance the other way.
I'm a little green when it comes to this stuff so excuse my ignorance.
Any thoughts or concerns would be greatly appreciated. Thank you

What do you mean by "vintage" 2015 STI wheels? The factory wheels for the '15 STI are 18x8.5 +55 with 245/40 , not 17x8.

If going from your current size to your quoted size of 17x8 the speedo will be off by 0.54%, so like you said nothing to worry about, with 12.7mm of poke on both sides. This isn't much to worry about clearance wise and will work.

However if going to 2015 STI factory wheels the speedo will be off by -0.98% with an extra 19.1mm in both directions. Both will work with the GH Mazda6, however if going to 8.5 you should use an offset in the low to high 50s, so the 15+ STI wheels will work fine for that purpose.

Thanks for that. Appreciate the help. Yeah, you are right. They are the 2015 WRX stock wheels, not the STI's. I was looking at the STI's initially being the 18x8.5's thinking they'd be too wide and throw the speedo out too much so moved on. Good to know both would work although I think I'll stick to the 17x8's Thank you again.
.