another tire size question

[fastlif]

I have American Muscle gt4 replica wheels in 18x10

Style: GT4 Finish: Hypercoated
Size: 18x10 Centercap Size: Large (2-1/2")
Back Spacing: 7.2" (184mm) Offset: +45mm (1.8")
Bolt Pattern: 5x4.5" (5x114.3mm) Fitment: 2005+ V6, GT,
including Shelby GT500

right now I have MT 305/35/18, I want a taller tire as this looks too small. This is not much of a track car but I want traction, with the MTs it still spins the tires in 2nd at 40ishmph. I would love to have a 305/40/18 but I don't think the Nitto 555r will handle it, the MT nor the NT05r is available in that size. My choices are 285/40/18 nt05r or 315/40/18 nt05r, or 305/40/18 nt555r. The car has FRPP lowering springs.

I prefer the wider 315/40/18 but not sure it will fit and I'm scarred to order $600 worth of tires that scrub. Here are some pics of the car now. Do you think 315/40/18 will be ok? All opinions appreciated!!

the MT 305/35/18 is almost exactly 26", fender is 28"

 

[XtremeS10]

Are you worried about the width of the 315 or the height? I am running a 315 on mine with no problems at all, could probably fit the 325 40 from m and h if I wanted to... I also took off the bump stop bracket on the inside of the wheel well

 

[fastlif]

The height mainly. I haven't seen anyone run these wheels. It's either stock size or TF, CCW type customs.

 

[XtremeS10]

The height mainly. I haven't seen anyone run these wheels. It's either stock size or TF, CCW type customs.

Height shouldnt matter an 18" wheel is an 18" wheel I am going to be running a 28" tall tire on lowering springs

Keep in mind you will raise the ride height with a taller tire a bit so compensate a little for that, are you running a lowering kit?

I don't think from your first pic you would have an issue stuffing the NT05R in there

 

[fastlif]

Height shouldnt matter an 18" wheel is an 18"

offset and backspacing might matter. Lol.

The 315/40 will only leave a little more than 1/2" gap(I think) and a good bump could scrub the fender.

I'm really thinking I'm gonna try the nt05 in 315/40 and just pray.

 

[XtremeS10]

offset and backspacing might matter. Lol.

The 315/40 will only leave a little more than 1/2" gap(I think) and a good bump could scrub the fender.

I'm really thinking I'm gonna try the nt05 in 315/40 and just pray.

Well I know some guys with the lowered cars say if you hit a hard bump you will rub a little but I really haven't heard too much about the 28's, like I said I will have less than 1/2 gap and will be driving my car a lot if you wanna wait some I can let you know, though I will be running a bogart wheel with them

I am trying to think I swear I saw a 27.5 drag radial somewhere m/t makes for the 18" wheels