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I’m new to the forum and thought I should introduce myself. I’ve been using my G37x as a daily for about a year now; before that, I had an IS300 and a few DSMs. It’s been really nice to have something with some power and reliability. The G37 is bone stock for now, but I do have some improvements in mind. Most of it is pretty basic stuff, but there’s one that might pique some interest.
I’m not happy with the donut spare. I know it’s pretty well documented here that a full size won’t fit, but I’m stubborn and am itching to use my rotary cutter. I’ve taken a few measurements and I think it might just work. Let me go ahead and apologize for the MS Paint job. I had Photoshop on hard drive that recently died. My hands-on measurements have been pretty crude – am stripping the trunk tomorrow to get more accurate ones.
Starting with the first picture: The spare tire measures 145/35/17 – so I worked out that the diameter of the spare is 533.5 mm (17” = 432mm, plus 102mm for the aspect ratio [145mm*.35*2]). Including rubber, the spare is 330 by 270 pixels. I did the same thing with the full-size tire’s measurements and got 700mm, or ~28% bigger, which is represented by the blue lines.
You can see from the second picture that the tire is definitely going to have to be moved inboard. Luckily, there are a few spacers that can be modified or removed to make room, as indicated with the red arrows. 84933M might need additional cutting since a full-size tire is about 3.2” taller. I haven’t fully explored my options for addressing the height difference yet, that’s another thing that’ll have to wait for the trunk to be stripped.
Let me know what you think and if you want updates.
Welcome to the site, looks like you've started w/ an interesting project, look forward to the end result. FWIW the spare should be 145/80/17 w/ a diameter of 663mm or 26.1". OEM tire sizes would be 225/55/17 diameter of 678mm or 26.7" or if you have the 18" set a 225/50/18 683mm 26.9"
Welcome to the site, looks like you've started w/ an interesting project, look forward to the end result. FWIW the spare should be 145/80/17 w/ a diameter of 663mm or 26.1". OEM tire sizes would be 225/55/17 diameter of 678mm or 26.7" or if you have the 18" set a 225/50/18 683mm 26.9"
Thanks!
I definitely should have double-checked my numbers. Since I won’t be doing as much cutting, I’ll have more time to fabricate something to cover the wheel and keep the trunk clean.
