Why no spare option for 20's?

[Gyascutus]

Can someone explain exactly why they don't give 20's the option? I wouldn't feel comfortable driving without a spar (I know they still come with the goo and air kit). I'm guessing one could buy their own spare but would it fit in the spare well?

Otherwise I would stick with the stock or foundry 18's. Also curious what size the spare is and if the 18's would fit in the spare well.

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[dwaleke]

On the performance pack cars my bet is because a spare wouldn't clear the front brakes. Not sure why it is not offered on the non PP cars.

 

[MikeAZ]

Can someone explain exactly why they don't give 20's the option? I wouldn't feel comfortable driving without a spar (I know they still come with the goo and air kit). I'm guessing one could buy their own spare but would it fit in the spare well?

Otherwise I would stick with the stock or foundry 18's. Also curious what size the spare is and if the 18's would fit in the spare well.

You'll be able to buy the OEM spare through Ford Parts - guaranteed to fit in the well.

Best explaination I've seen for the lack of the spare option with the 20" wheels is that the overall diameter of the spare causes too much stress on the differential when used with a 20" wheel on the other side.

 

[JimmyTwoTimes]

You'll be able to buy the OEM spare through Ford Parts - guaranteed to fit in the well.

Best explaination I've seen for the lack of the spare option with the 20" wheels is that the overall diameter of the spare causes too much stress on the differential when used with a 20" wheel on the other side.

This. Always remember to only put a spare on a non-drive wheel on a car with a limited slip.

 

[Gyascutus]

What size is the stock spare?

 

[embraceentropy]

I bought a GT with the 20" rims a couple of days ago and got the salesman to agree to give me the spare tire kit for free to seal the deal (along with rubber mats and a third key fob). I got the call today from the dealership saying they couldn't provide the spare since I had the 20" rims. I know the issue with having two different tire outside diameters on an LSD. However, is there any issue with putting the spare of different diameter on the front? If so, I would like to still demand the tire kit to have in case I had an issue with a front tire. Thoughts?

 

[theman]

I haven't rolled around with a spare in any performance car driven in the past 15 years with 18" or larger wheels on them... most the Supras, RX, and M3s I've had 18-19" wheels(fitted up many 19"+ on other rides through my garage doors), and the 35 series sidewalls on any of these cars barely go down with no tire pressure in them, whether runflat or not.
Take a tire plug kit with you, pointed nose pliers, and a 12v portable air compressor... $20 altogether and total weight in car of 5lbs, vs 50ish for full spare wheel. 99% of flats are from something pluggable(nail,screw, etc.), saving a good tire. once you use fix-a-flat crap the tire is out of balance and ruined internally anyway.
jack up your car, spin the tire to find foreign object, remove, plug it, add air. done as fast as tire change anyway, without hassle of putting it back on all over again and driving with a sub-par tire on until you get the other fixed.

 

[Blk2015GT]

As I said earlier, here's the issue:

OEM spare tire kit- 18" wheel 155/60R18. This tire has an outside diameter/height of 25.3"

OEM 20s'- 265/35R20. This tire has an outside diameter/height of 27.3" (FYI 275/35x20 have a height of 27.6" for the aftermarket wheel guys like myself.)

Now you can see the issue, the 20s are 2-2.3" taller a tire than the spare tire. Car will lean to that corner big time riding on the spare and could ruin suspension etc. (I'm sure it'd be ok for a mile or 2 at low speed to a tire shop though).



SOLUTION- Take your OEM spare and buy a new tire for it with a taller sidewall to get the height closer. You can get a Perelli 135/80R18 tire from Tirerack for $97 that will bring you to 26.5" tall. 1.2" better than tire on the OEM spare

If you can find a 145/80R18 if would be even closer at 27.1"

 

[Skenneyjr]

The issue then becomes whether or not you can fit the full diameter spare in the spare tire well in the trunk. Also, fitting the damaged tire into the trunk.....hard to fit factory 18s through that opening....lol.

Where are y'all getting the jack and tire iron for the spare? I'd like to keep one of my "off season" tires in the trunk in case I ever get a flat, especially on a road trip.

 

[dgc333]

As I said earlier, here's the issue:

OEM spare tire kit- 18" wheel 155/60R18. This tire has an outside diameter/height of 25.3"

OEM 20s'- 265/35R20. This tire has an outside diameter/height of 27.3" (FYI 275/35x20 have a height of 27.6" for the aftermarket wheel guys like myself.)

Now you can see the issue, the 20s are 2-2.3" taller a tire than the spare tire. Car will lean to that corner big time riding on the spare and could ruin suspension etc. (I'm sure it'd be ok for a mile or 2 at low speed to a tire shop though).



SOLUTION- Take your OEM spare and buy a new tire for it with a taller sidewall to get the height closer. You can get a Perelli 135/80R18 tire from Tirerack for $97 that will bring you to 26.5" tall. 1.2" better than tire on the OEM spare

If you can find a 145/80R18 if would be even closer at 27.1"

Whether you have the base 235/55-17, 235/50-18, 255/40-19 or 265/35-20 they all have the same outside diameter of 27.3" only the GT PP rear 275/40-19 is larger at 27.7"

The optional spare tire is available all versions except those with summer tires, you can get it with the Aniversery package which has 255/40-19 all season tires.

I can understand the GT PP because the wheel won't fit over the PP brakes but it will clear the brakes on all other versions so it's not an outside diameter thing. The digging I have done the spare has a 185/55-18 tire.

 

[plc268]

Whether you have the base 235/55-17, 235/50-18, 255/40-19 or 265/35-20 they all have the same outside diameter of 27.3" only the GT PP rear 275/40-19 is larger at 27.7"

The optional spare tire is available all versions except those with summer tires, you can get it with the Aniversery package which has 255/40-19 all season tires.

I can understand the GT PP because the wheel won't fit over the PP brakes but it will clear the brakes on all other versions so it's not an outside diameter thing. The digging I have done the spare has a 185/55-18 tire.

Usually full size tires will fit if you deflate them first.

 

[kcphoto21]

Is there an aftermarket spare tire I can buy?

Many thanks.

 

[Blk2015GT]

The issue then becomes whether or not you can fit the full diameter spare in the spare tire well in the trunk. Also, fitting the damaged tire into the trunk.....hard to fit factory 18s through that opening....lol.

Where are y'all getting the jack and tire iron for the spare? I'd like to keep one of my "off season" tires in the trunk in case I ever get a flat, especially on a road trip.

Deflate the tire a bit. All GTs at least come with the air pump. 1" extra should fit though.

Whether you have the base 235/55-17, 235/50-18, 255/40-19 or 265/35-20 they all have the same outside diameter of 27.3" only the GT PP rear 275/40-19 is larger at 27.7"

The optional spare tire is available all versions except those with summer tires, you can get it with the Aniversery package which has 255/40-19 all season tires.

I can understand the GT PP because the wheel won't fit over the PP brakes but it will clear the brakes on all other versions so it's not an outside diameter thing. The digging I have done the spare has a 185/55-18 tire.

I understand that. Just offering a better tire option for the spare than OEM that may ride a bit better.

 

[Old 5 Oh]

If you look closely at which Mustangs can and cannot be ordered with spare tires, you'll see that you can get the spare with all-season tires and not with summer tires. That's the issue. Ford apparently has their legal knickers in a twist over mixing the different driving dynamics of three summer tires with one wimpy spare. There is NO reason other than that one that you couldn't use the factory spare (gently) with the 20s.

 

[Blk2015GT]

If you look closely at which Mustangs can and cannot be ordered with spare tires, you'll see that you can get the spare with all-season tires and not with summer tires. That's the issue. Ford apparently has their legal knickers in a twist over mixing the different driving dynamics of three summer tires with one wimpy spare. There is NO reason other than that one that you couldn't use the factory spare (gently) with the 20s.

Well or the Brembos ;)

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