orange3.9stang

Had read about a couple of Shelby owners who put Full Size Spares in their Trunks. One guy cut the trunk floor around it and it looked pretty good (pic below). Another guy with a 2010 Shelby put a 245-40/19 tire on a replica GT500 wheel he got from American Muscle ...
2007 - 2011 Shelby GT500 Spare Tire - Shelby Forums - Carroll Shelby - GT350 - GT500
... he claims in order for it to fit, he has to deflate the tire and it sticks out past the trunk floor 3-4". Don't think this is the same guy who cut the trunk floor around his spare though as he mentions the raised trunk floor now gives him depressions on either side to put stuff.

This got my curiosity up, so I yanked one of my Road Wheels off of my car (stock MCA 18x8" & 235/50-18 Pirelli P-Zero) to see for myself. Well, it just barely fits down in the spare well and YES it had to be completely deflated in order to squeeze down in there. It sticks up past the trunk floor about 1.5" (see pics below), which is much better IMO than the 3-4" that Shelby owner is dealing with.

If you wanted a more "flush" spare, a 18x7" aftermarket wheel could be used along with a narrower tire:
225/50-18 = 26.858" dia. which is 98.6% of the 235/50-18 dia. (27.25")
or
215/55-18 = 27.311" dia. which is 100.2%
... either of which would be ok for mounting on the rear.

If this same 18x7" wheel would fit on the BACK of an 2011 Brembo GT:
225/50-18 = 26.858" dia. which is 99.4% of the 255/40-19 dia. (27.03")
or
215/55-18 = 27.311" dia. which is 101.0%
... again, either would be ok for mounting on the rear (but not up FRONT).

I do however have TWO concerns about putting a deflated road wheel down in the spare well:
1) What if while sitting in the trunk well deflated for a couple of years, the tire bead separates from the rim ... would I be able to get it to re-seat with this tiny pump ??
2) How long will it take for the Ford supplied pump to fully inflate this tire along side the road ??

I was tempted to TEST my pump to see how long it would take, but since it is designed for "Emergency Use" it may be only good for 1-2 tires before it's junk !!
Reason I say this is I had a portable pump like this years ago that I tried to use to pump up a tire from "0 PSI" and it got so hot it started smoking before tire was fully inflated.

Doug

monkeystash

I bought a used 07-09 GT500 wheel for $50 and a used 255/45/18 from bestusedtires.com for $60. This fits in my spare well fully inflated. It does stick up 2-3 inches. I have a brembo car and the tire diameter is almost identical.

OAC_Sparky

1) If the bead seperates, you might have a pretty hard time getting it to reseat, you usually have to get the pressure up pretty high (40-50PSI) before it pops. The emergency pump doesn't pump fast enough.
2)From completely empty, probably 7-10 minutes.

Personally I hate the notion of not running a real spare, but unless you can keep 2-5 PSI in the spare I would rather use an undersized tire on the rim that stays inflated, and swap tires back to front in the event the flat was on the rear tire.

David Young

Another 'well done' write up Doug.

OAC Sparky is right. I put some new rear tires on my riding mower. It does take the 'fast' fill from an air compressor to get the bead to seat. I tried with my hand pump and battery powered pump, neither one worked.

orange3.9stang

I've got Michelin X-Ice Xi2 215/65-17 Snow tires on 17x7" wheels that I bought a few weeks ago for this car.

It's been raining all morning and out of bordom I grabbed one and deflated it to see if the narrower tire & rim would really be shorter in the spare tire well.

No such luck ... the larger dia. of this tire (28" vs. 27.2" of stk. Pirelli), will not allow it to go down into the spare well even fully deflated.

Kind of thought this may be the case considering the Pirelli was pretty snug, but it was worth a shot anyway.

Someone with a V6 - M/T car with the base 225/60-17's BFG tires needs to see if they can get one of these deflated road wheels to fit down in the spare well. It's 27.6" diameter is between the 18" Pirelli & the 17" V6 A/T size tire I've got for snows so it may not fit either.

In case anyone had not seen them before, here's a pic of these winter tire/wheels ... mounted 1 side only to test fit ... hopefully there will be no need for "snow shoes" until late November / early December.

Doug

shadowstang03gt

would a 03 cobra spare fit the car?

Ltngdrvr

I really don't understand why anyone has a problem with a "mini" spare for their car. Even if you were to run it on the rear you would only have it on there long enough to get you somewhere that a repair to the original or a replacement could be put on. The difference in diamater from one side to the other for that short distance would be the same as if you were going around a circle and the clutches in the differential are made to allow for this. So long as you stay out of the power while you have the spare on it isn't going to put hardly any extra wear on the clutches in the differential.

Now, if you had a detroit locker differential then it would be a different story, pop-bang, pop-bang all the way down the road, but that's not the case here.

Get a mini-spare off ebay and throw it in there and stop worrying.

shadowstang03gt

i agree. Just have to figure out which one will work

Ltngdrvr

On the rear, any of the 5 lug spares will work on either the GT or V6, on the front the 17" mini spare will fit the 2011 V6, maybe the GT, most likely not the brembo. On those bigger braked cars you might have to swap front to back original wheels for a front tire flat.

shadowstang03gt

do u think an 03 cobra spare would fit?

Ltngdrvr

Fit like I stated above, maybe fit a 2011 GT front, maybe. Fit the rear just fine.

orange3.9stang

Just posted this in another thread where someone was asking about a "Spare for a Boss 302" and thought I should add this to this thread as it pertains to GT500 / 2011 Brembo GT Owners as well as future 2012 Boss 302 owners ...

18" wheels were std. on 2007-09 GT500's and these cars all had the same 14" Brembo front brakes as 2010-12 GT500, 2011-12 Brembo GT's, and 2012 Boss 302 that all now come std. with 19" wheels.

A 225/50-18 tire will mount on an 8" wide wheel (no wider though) and it's 26.858" dia. MAY just fit down in the trunk well without deflating ... there are 29 choices in this size on TireRack & 14 on DiscountTireDirect. This tire is only 0.06% smaller than the Boss/GT500 fronts & Brembo GT F/R (255/40-19 = 27.03" dia.) and the SAME basic dia. as the Boss/GT500 rears (285/35-19 = 26.854" dia.), so there should never be a differential issue on cars with a std. T-Lok.

The 2007-09 18" GT500 wheel is 9.5" wide (too wide for this spare tire), so I did some searching on T-R & D-T-D for narrower rims that will fit GT500/2011 Brembo GT. Well T-R showed nothing but D-T-D showed various 18x8" Drag DR-34 wheels ($150 each) that supposedly will fit over the Brembos.

So there you go, you Brembo owners should now have an easy and relatively inexpencive "full-size" Spare tire / wheel option (to research a little further) ... hopefully this is the answer !!

Doug

cdynaco

It probably would fit. My Marauder mini is T155/80x18, diameter is 27.76. It almost fits the well but at a slight angle, so the center of the wheel sits high. That's why I have it in upside down.



** Be sure to turn traction control off when using a different size tire per Ford.

orange3.9stang

Reason I say a 225/50-18 SHOULD FIT down in the spare well is I grabbed one of the wheels off of our 2003 Grand Caravan right after putting new Tiger Paw tires on it (215/70-15 = 26.850" dia) in early November and the diameter fit down in the well without deflating. This is theoretically only 0.005" smaller in dia. than my suggested 225/50-18, so I'm pretty confident it will fit plus it should not stick out of the well more than 1-1.5" since my O.E. Pirelli 235/50-18 (deflated and also on an 8" wide wheel) only stuck up 1.5".

Doug

shadowstang03gt

i got a factory mini spare out of a 19inch 2011 GT. u think it will clear the brembos?

orange3.9stang

Reguardless of factory "Road Wheel" size, all 2011 GT Temp Spares are 18" ... if this clears the Brembos, wouldn't you think Ford would be suppling them on Brembo equipped cars ?? Instead, they have been supplying the Tire Mobility Kit on the 2007-up GT500 and the 2011-12 GT w/ Brembo.

There are certain 18" wheels that clear the Brembo brakes but many that don't. There are also 19" wheels that will not clear the Brembo's (GT/CS for sure).

The 18" Temp Spare was NEW to 2011 (all prior GT's had 17"), but again if it fits I'd think Ford would be suppliyling Brembo cars with it rather than the silly Mobility Kit.

Doug

shadowstang03gt

i wanna try and install it. but its so **** cold. i hope it fits. A lot of cars dont come with a spare anymore. i mean geez the V6's didnt even come with one.