[Phacade]

So I'm patiently waiting for some new Rota Grids, which will only take forever to ship to me, 16x7 in Steel Grey, +40 offset. Now then comes the tires question. I've got the Saleen/Eibach suspension (basically an Eibach Pro kit), which gives me a mild 1.6" drop on my SVTF. Now the query. I got the +40 offset because, well it looks cool, but I don't want to rub either. I'm stuck between two tire size choices for these:

1). 205/50/16?
2). 215/50/16?

Both tire sizes are within about the size size as the 215/45/17's I'm running now, and yes I do want the extra sidewall protection thanks to an unfortunate meeting with a rock about the size of your head last year, but which will be best for my car and tires? I want good looks without the worry of rubbing either. Whatcha think?

My car currently:

 

[Insane]

I personaly think 215/45/16 is the better size for you. It has the same sidewall height as 205/50/16.

 

[Phacade]

I personaly think 215/45/16 is the better size for you. It has the same sidewall height as 205/50/16.

Well that more or less defeats the whole reason of going 16" IMO, I want the extra sidewall height. The big question is if I'm going 205 or 215?

 

[TriniZX3]

215/45/16...extra sidewall height does not translate to better performance or looks. just dont hit any curbs or rocks. many tires have ribbed edges for curb protection. as long as you are a good driver, the chances of you hitting another rock are very slim. id rather have a better handling tire which is what a tire is designed for (handling)than a better protecting tire or which its not designed for.

 

[Phacade]

Totally understand, however paranoia is a powerful motivator. If I was going to stay with a 45-height tire, I'd have gotten some 17" rims again. 50-height tires will give me about the same performance, and I'm determinted to go 50, my only question is if I should go with a 205-width or a 215-width.

 

[Insane]

Right the 205/50/16's have practicly the same sidewall height as 215/45/16's so if your willing to go 205/50/16's then why not 215/45/16's?

 

[thenorm]

there is a high probability of rubbing with a 215 tire. 205 will have a lesser chance of rubbage.

if you havent got tires yet, i recommend
http://www.tirerack.com/tires/Sizes.jsp?make=Goodyear&model=Eagle+F1+GS-D3
they're awesome tires, and cheap cheap cheap!

 

[dirtbrown]

Right the 205/50/16's have practicly the same sidewall height as 215/45/16's so if your willing to go 205/50/16's then why not 215/45/16's?

i totally agree[headbang]

ive used all these tire sizes and I have a 16x7" rota...with a 40mm offset...the 205/50 will be ideal for what you want...the 215/45 will be a bit pricey but is about the same size just a bit wider....you should be fine with either the 205/50/16 or the 215/45/16 ...I wouldent do the 215/50 thats just too chunky...it will look silly.

 

[Insane]

^^ I just got the same tires on my car two days ago and yes they are great tires! I believe they are normally around 140-150 each! I got two tires and 2 day shipping for 120ish I believe.

 

[Phacade]

I hear ya, and while I definitely appreciate the advice, my goal is to maintain my drop and get better sidewall protection at the same time...otherwise I wouldn't be going down to 16" wheels. The tire calculator tells me differently on that 45-height tire. Work with me here:

Stock 215/45/17 tire:
Sidewall: 3.8 in
Radius: 12.3 in
Diameter: 24.6 inch
Circumference: 77.3 in

215/45/16:
Sidewall: 3.8 in
Radius: 11.8 in
Diameter: 23.6 inch
Circumference: 74.2 in

So it has the exact same sidewall but its a shorter tire, in other words, it would negate my drop and give me no better sidewall protection. Why bother going to 16" wheels at this point at all? My loss of 1" goes into more gap instead of sidewall protection. No thanks. Now look at this:

215/50/16:
Sidewall: 4.2 in
Radius: 12.2 in
Diameter: 24.5 inch
Circumference: 76.3 in

This choice gives me more sidewall protection and yet the same diameter wheel, in other words, I keep my drop. The last choice:

205/50/16:
Sidewall: 4.0 in
Radius: 12.0 in
Diameter: 24.1 inch
Circumference: 75.6 in

This seems to have a little loss in drop, middle of the lane in sidewall protection, but may rub less. I like either of the last choices. I'm planning on a 215/50/16 or a 205/50/16 for sidewall protection and to maintain my drop, but which of these two? Thats the question.

 

[dirtbrown]

look at the diameter of the 215/50...I think the logical choice to aviod problems are the 205/50 or the 215/45...and sometimes those calculaters dont do anything for you because tire sizes vary by brand.

 

[WD40]

Why the drop in diameter, for a street wheel?
If so, you really should have opted for the 45mm offset with the drop you have.

As far as the recommendations for a 215/45/16.
That tire is a full INCH shorter than the stock 215/45/17.
You speedo is going to be way off, and even though the car is lowered, you'll open up the fender gap quite a bit with that short of a tire.
I run that size (215/45/16) for AutoCrossing, (on 42mm offset wheels) but I sure wouldn't run it on the street.
That's way too short for an SVTF.

Of your 2 choices, the 215/50 is the closest in size to the stock SVTF tire, though I'm afraid you may have rubbing issues due to the 40mm offset.

STOCK:
215/45/17 - 24.6" diameter
205/50/16 - 24.1" (on a 6.5" wheel...7" wheel will be even shorter, most likely at 24")
^^^And again, speedo error will be significant.
215/50/16 - 24.5" (on a 7" wheel)
^^^Much closer to stock diameter, but the problem is, there's an extremely limited selection in that size.

Now the other option is a 205/55/16, which a lot of us SVTF owners use for winter tires.
But then again, that's a couple 1/10ths taller, and you're most likely going to rub with a 40mm offset wheel.
I have mine on 45mm offset (Koni springs-very small drop) and have no rubbing problems.

EDIT
I guess I'm just not that quick on the keyboard...
I started my post well before 11:00, and I see 2 others snuck in in between.
I did go to Tire Rack to check the tire diameters, and didn't use one of the calculators.
That's when I found out there's not very many tires available in a 215/50/16.

Phacade, I now see why you want the 16's (sidewall height/wheel protection),
but to be safe I'd run a 45mm offset with that drop to prevent any chance of rubbing.
BTW, the 205/50/16 only has 2/10ths more sidewall height than the 215/45/17. You're really not gaining anything with that size.
215/50/16, or 205/55/16 are your only 2 choices for an appreciable increase in sidewall height.

 

[dirtbrown]

wd40 why do you think a 215/45 is too short of a tire for an SVT??? besides the fact that my speedo is off 5mph?? whats the difference between the 215/45/17 and the 215/45/16?? I know a full inch in diameter is lost but wouldent that actually help the car?

 

[WD40]

Sure, it'll help on the AutoCross course to get out of the hole, (that's why I use it)
but then again at 75mph on the freeway it ends up turning a few hundred more revs.
Being that 6th gear isn't an overdrive on the SVTF, I don't think a shorter tire is a good thing if you're doing a lot of highway driving.

 

[dirtbrown]

I do alot of HWY driving on this current set-up...is it not a good idea because of the small chance of increase in fuel consumption?

 

[WD40]

I'm not nearly as concerned with the mpg, as I am with the wear and tear on the engine and transmission due to the additional rpm.
(And wheel bearings and CV joints...)

 

[dirtbrown]

^^I think that might be a bit extensive but I see what you mean....I mean on the Hwy at 70mph im at 3100k is this out of the ordinary??

 

[Phacade]

About the same though. The amount of revolutions difference on your 23.6 inch-height tire and my 24.6 height tire is about the same really, adding exactly 35 revolutions per mile really. (819 revolutions per mile -vs- 854 revolutions per mile) On my stock 215/45/17s, I'm hitting about 3050RPMs at 70mph myself...no big loss there.

Mind games and second guessing. I do it constantly. My only concern is if I go 215/50/16 that I might rub a bit on the +40 offset, but I might not on 205/50/16....or should I have gone for +45 offset instead? Overall diameter should be near identical with my 17s but the offset does give a bit of pause. Still, trial and error I suppose. The +40 should look a bit better since they'll sit more flush with the wheel-well.

 

[WD40]

It's a hair over 2,900rpm with the 17's.
I know, it doesn't seem like a huge amount, but it all adds up.

I hope we didn't scare Phacade off..
Though, I hope he appreciates the discussion, as it does pertain to his tire choice. []

EDIT:
See...there I go again.
Taking too long to write something while the other person replies...
(Actually, it wasn't the writing, it was me calculating the revs)

Back to the subject.
If it were me, I'd most definitely opt for the 45mm offset.
If it looked that bad, it's a lot easier and cheaper to get a 5mm spacer if you just had to move the wheel out further.
Course, they cause there own problems with extra stress on wheel bearings, etc...

 

[TriniZX3]

sometimes if you go the manufacturers website they will give you the exact specs for the each size tire. i find that diameters and width vary widely depending on what brand. with your drop, a few tenths of an inch might make a big difference.