What Size Wheels & Tires Up Front?

[Al Guapo]

I need new rims and tires. I want the same size tires on all corners because I corner.

The suspension only has koni yellows and I'll install the steeda comp springs when I do the rims & tires.

For the front only...

1) Can I fit 18x10 with 275/35/18?

or

2) Am I better off with a 18x9 with 275/35/18?

Thanks.

 

[Corpo]

I have run 275/40/18 on a 18x9. I have also ran 275/35/18 on 18x9.5. My experience on the two, the first combo no issues. the second i had some rub, only during a hard turn around in a autox course. not bad though. but i do believe it caused my cords to show on that tire just in the edge. hard to say really. the tire was almost done anyway. i run -2.5 degree's of camber.

 

[Al Guapo]

I have run 275/40/18 on a 18x9. I have also ran 275/35/18 on 18x9.5. My experience on the two, the first combo no issues. the second i had some rub, only during a hard turn around in a autox course. not bad though. but i do believe it caused my cords to show on that tire just in the edge. hard to say really. the tire was almost done anyway. i run -2.5 degree's of camber.

What wheels & offset were the 18x9?

Did the tires seem to stick out too much on the 18x9?

When cornering hard, did they feel "floaty"?

I ask this because I'm considering piecing my own rim and tire package from American muscle. I need as much grip as I can get with a turbo.

Thanks.

 

[Corpo]

First set. Americanmuscle gt4 rims. they looked flush installed. didn't feel floaty to me.
Second set. gt500 take off's. also fit flush and had no floaty issues.


The gt4's are in my Sig. its kinda dark but you can see they look good.

 

[Al Guapo]

First set. Americanmuscle gt4 rims. they looked flush installed. didn't feel floaty to me.
Second set. gt500 take off's. also fit flush and had no floaty issues.


The gt4's are in my Sig. its kinda dark but you can see they look good.

I want to get the 18x9 bullitt anthrecite from AM. I checked AM and your GT4s have a 40mm offset compared to a 30mm for the bullitts.

I was using this chart and it seems like that the 30mm offset may stick out a tad out of the fender. What do you think?
http://www.rimsntires.com/specs.jsp

 

[Corpo]

I think another cm would still fit under the fender.

 

[Al Guapo]

I think another cm would still fit under the fender.

Now that I think about it... yeah it is only 1 cm. Probably couldn't even see it if they were side by side. Thanks.

 

[tjm73]

Now that I think about it... yeah it is only 1 cm. Probably couldn't even see it if they were side by side. Thanks.

1cm = 10mm = 0.393". That seems like a lot.

 

[mot250]

18x9.5 will fit on all corners with 275/40s. No rubbing (these have seen a number of track days) and I've got Steeda Comp springs on my car as well. They also fit just barely inside the top of the fender line if you drop a string from the top.

I don't know the backspacing but they are Steeda Pentars.


Sent from my iPhone using Tapatalk

 

[Norm Peterson]

After a little digging, the Pentar wheels are +45 mm offset, same as the SVT/GT500 wheel.

Al - +30 mm is a SN95/NE offset. See if you can find the same wheel design with an offset somewhere between +40 and +50.


FWIW, I'm running the GT500 wheels with 255/45 Goodyear Asymmetrics, which measure up a lot closer to 265 wide on 9.5" rims. It's the OE front tire and wheel fitment on the '08 GT500, and I've never had any rubbing on my GT no matter what combination of bump and steering was involved. Stock springs.

FWIW #2, I'd expect a 275 wide tire on 9" rims to have somewhat greater lateral distortion than this . . . and R-comps a little more still

Norm

 

[Al Guapo]

18x9.5 will fit on all corners with 275/40s. No rubbing (these have seen a number of track days) and I've got Steeda Comp springs on my car as well. They also fit just barely inside the top of the fender line if you drop a string from the top.

I don't know the backspacing but they are Steeda Pentars.


Sent from my iPhone using Tapatalk

18x9.5 is the perfect size IMO The only problem is the lack of selection.

After a little digging, the Pentar wheels are +45 mm offset, same as the SVT/GT500 wheel.

Al - +30 mm is a SN95/NE offset. See if you can find the same wheel design with an offset somewhere between +40 and +50.


FWIW, I'm running the GT500 wheels with 255/45 Goodyear Asymmetrics, which measure up a lot closer to 265 wide on 9.5" rims. It's the OE front tire and wheel fitment on the '08 GT500, and I've never had any rubbing on my GT no matter what combination of bump and steering was involved. Stock springs.

FWIW #2, I'd expect a 275 wide tire on 9" rims to have somewhat greater lateral distortion than this . . . and R-comps a little more still

Norm

Thanks for checking!

I agree that a 275 may have some lateral distortion which is why I want 18x10.

These are the wheels I was thinking about putting on all corners
http://www.americanmuscle.com/black-2005-deep-dish-bullitt-wheels-18x9-18x10.html

They actually have the same offset of 45mm as the GT500 but are a .5 inch wider.

Do you think these would fit up front?

 

[Norm Peterson]

As long as the offset remains at +45 mm, widening the rim from 9.5" (as in the GT500) to those 10" AM Bullitts will increase both the backspacing and the front side spacing by 1/4".

Comparing against the known situation up front - 255/45's on 18x9.5 - the tire section width (across the sidewalls) of a 275/40 on 10" goes up a little more than that, but this is somewhat variable due to different tire companies molding their 275/40's to slightly different actual dimensions. IOW, I think when you're getting this close you probably need to know the specific tire before trying to predicting its clearance. I might have been able to give you a better idea if I'd ever tried to find out how close my tires get under various circumstances, but I figured that Ford had already done that and never bothered.


Norm

 

[Norm Peterson]

So I "measured" the clearance between my 255/45's on 9.5" wide wheels and the strut - there is less than a finger thickness of clear space. IOW, not enough room for 10's and 275 wide tires without a small spacer. But there's not a whole lot of room to go out, either. I can almost see the tire looking straight down, and that's with -1.8° camber.

I have no idea if production tolerances are "loose" enough to where 275/40's on 10's/+45 won't fit mine without a fair amount of extra effort, but might on somebody else's.


Norm

 

[Cobra SS]

Al, here's the 285's on the front

 

[Al Guapo]

As long as the offset remains at +45 mm, widening the rim from 9.5" (as in the GT500) to those 10" AM Bullitts will increase both the backspacing and the front side spacing by 1/4".

Comparing against the known situation up front - 255/45's on 18x9.5 - the tire section width (across the sidewalls) of a 275/40 on 10" goes up a little more than that, but this is somewhat variable due to different tire companies molding their 275/40's to slightly different actual dimensions. IOW, I think when you're getting this close you probably need to know the specific tire before trying to predicting its clearance. I might have been able to give you a better idea if I'd ever tried to find out how close my tires get under various circumstances, but I figured that Ford had already done that and never bothered.


Norm

I was planning on using Nitto NT555 275/40/18 or 275/35/18.

So I "measured" the clearance between my 255/45's on 9.5" wide wheels and the strut - there is less than a finger thickness of clear space. IOW, not enough room for 10's and 275 wide tires without a small spacer. But there's not a whole lot of room to go out, either. I can almost see the tire looking straight down, and that's with -1.8° camber.

I have no idea if production tolerances are "loose" enough to where 275/40's on 10's/+45 won't fit mine without a fair amount of extra effort, but might on somebody else's.


Norm

So basically my choices are 18x9 or 18x9.5.

Do you think 275/35/18 nitto NT555s are ok on a 18x9?

Thanks.

Al, here's the 285's on the front

Thanks

 

[Norm Peterson]

275/35 is a pretty short tire (only about 25.6" tall) and will add about 3/4" to the wheel-to-fender gap. Something like that is more of a dedicated track or autocross choice, where appearance reasons usually end up being excuses for not winning.

275/40-18 on 9" wheels with around +45mm offset should work though.

There's a guy who posts under the username 'Nuke' over on Mustangforums who is running 275/40's on 18x9.5's and who might be able to give you a direct review. I think he'll be dropping back to 255/45's next time around, but I think that's for personal appearance preference and tire tramlining reasons rather than rubbing.


Norm

 

[C-Liz-Go]

Norm, I actually understood everything you wrote here, and it has been helpful in my own tire quest (which for the last week has given me a friggin' headache).

Thank you.

 

[NEMustang]

I was planning on using Nitto NT555 275/40/18 or 275/35/18.


So basically my choices are 18x9 or 18x9.5.

Do you think 275/35/18 nitto NT555s are ok on a 18x9?

Thanks.



Thanks

Norm provided you with a lot of good information. On the street, I run an 18x10 with +40mm. I have a set of the Goodyear F1 Supercar tires from a GT500KR from Shelby...255/45/18 front and 285/40/18 rear. However, for the track, I run Enkei PF01 18x10.5 +38 offset with 275/35/18 all around. Norm is correct on sizing as these are about two inches smaller in diameter than my 285/40/18 tires. The 35s look small in the wheel well.

Check out this post and it shows my car on track at near full compression with 18x10.5 Enkei PF01 and 275/35/18 Hoosiers. The car is lowered two inches, plus another inch with smaller diameter tires...no rub:
http://www.s197forum.com/forum/showpost.php?p=1125302&postcount=21

The Enkei PF01 at 18x9.5 with either +35mm or +45mm are a great choice. These are light weight forged wheels (about 20 lbs vs. most this size at 30lbs.) I use the 18x9.5 with +35mm with no issues. You can also run up to a 285 on these...and they clear the Brembos if you have them or plan to run them.

BTW, if anyone want Enkei wheels, I can get a deal on them...PM me.