Honestly clueless, I've researched and searched, and this is just the sort of math that for the life of me I cannot wrap my head around.

Sometime in the next few months I plan to finally upgrade from my stock 17"s and get something with better fitment.

My car is an 05 G35 coupe, lowered ~1" front .6" back on Swift springs.

My first issue is rim fitment, I've decided on Enkei NT03+M for their price, looks, quality, and reputation. I contacted Enkei and they suggest
18x8.5 +38 / 18x9.5 +40, but elsewhere on the forums I saw that people were running
18x9.5+27 18x10.5+30 https://g35driver.com/forums/media-s...-m-wheels.html

I know what I want to achieve stance wise, and its essentially a nice clean look that would line up as even as possible with the profile of the car, trying to avoid crazy tire stretching/hellaflush, not afraid of some meat. Would the enkei suggested fitment look tucked and require loads of spacers at my dropped height? Would a compromise of running a more square 9.5/9.5 look proper?

Which ties directly into my second problem of what size tires would fit properly without messing up the VDC system?

I was hoping to use Nitto NeoGens, but its looking like they have to limited an amount of sizes to work? http://www.discounttiredirect.com/di...%2FPerformance

Thanks for any help you can provide, someday I'll be bale to wrap my mind around tire ratios and offset numbers...

 

On a 245/45 tire, the sidewall is about 110mm high.

Tire width = 245mm. Sidewall ratio is 45% of 245mm - 245*0.45=110.25

If you upgrade from a 245 to a 275, you'll want most likely a 275/40. 275*0.40=110

That should help you decide on the appropriate tire size once you compare the front to the rear - you'll want 110-112ish front and rear if that makes sense.

Hopefully someone else can chime in but that's how I've figured it in the past and I haven't had issues.

 

That thread you posted has your answer, go with the 265/35/18 and 295/35/18 combo. It looks to fit the wheels well and it fills the gap pretty good too.

You can get the Nitto INVO in that size which is a great tire.

 

definitely do the 18x9.5 and 18x10.5 you'll probably add spacers down the road with this set up as well.

The 295/35 is a pretty huge tire. See if you can find that in a 295/30

 

Those are terrible offsets for a coupe, worse than stock. Especially if you are lowered you want to be in the teens in offsets at least.

 

Can't comment on tire sizes for 18s cause I've never run them on my car,
but def go with the 9.5F/10.5R wheels.
Then slap on some 15mm wheel spacers to be somewhat flush.

 

+30 are going to need a lot more than 15mm spacers to be flush... More like 30mm spacers.... or at least 20-25mm

 

15mm spacers won't make it super flush but it will be close.
I guess it depends on how aggressive he wants his setup.

Fixed - added "somewhat" to my sentence.

 

are the offsets really that bad? I'll try to contact that original member for more information on how his wheels looked. I'm having a hell of a time finding a picture that sums up what I'm aiming for, but something that approaches this would be fine, , I'm just hoping to the the edge of the rim to line up with the fender, no crazy camber, I'd like to keep my alignment in stock specs.

I shouldn't have any rubbing issues right? Crap these tire options are expensive...

 

^ to get fitment like that my initial suggestion would work for you.
9.5F/10.5R with 15mm spacers all around, but you may still need to roll your rear fenders.
It just depends on how much travel your springs allow.
Esentially with the wheel spacers it would give u +12 offset up front and +15 offset in back.
You could actually even go with a 20" wheel spacer up front to match the flush fitment of the back.

Here's an idea of what a 9.5/10.5 wheel setup with +12 offset all around looks like.
Keep in mind your drop will be diff because these are 19" wheels on diff suspension.
This is for flush fitment reference only but it should help.

 

thanks for all the help guys, the 9.5/10.5 seems to be the right setup for how flush I'm wanting to get and with the right amount of concave on this rim design, and I think I'm beginning to understand tire sizes. thanks again for all of your help and patience