[Sienna.Guy]

While researching and comparing Spare Tire (Donut) sizing to full size 235/50 R20 (Width=Don't Care, Diameter=29.3").

Using Tire Size Calculator, I've come up with 4 options:
Stock: Spare tire is 155/80 R17 (Baseline: 6.1" width, 2.5" smaller diameter compared to Fullsize)
Option 1: Upgrade to 155/90 R17 (Same width (6.1"), 1.3" smaller)
Option 2: Upgrade to 165/90 R17 (0.4" wider, 0.6" smaller)
Option 3: Upgrade Spare tire set with new rim 165/85R18 (0.4" wider, 0.3" smaller, new rim +$$)
Option 4: Upgrade Spare tire set with new rim 155/90R18 (Same width, 0.3" smaller, new rim +$$)

Any and all the above is dependent of Spare tire well fitting. Maybe I can ditch the original hard cover for an oversized shower cap.

Has anyone done this or thought of doing this? What would be a good practical method of checking fitment? There appears to be about one inch around the circumference.

Also to consider, if inflated to 60 PSI, how much diameter does that increase vs non-inflated. I say non-inflated because I typically carry a portable air inflator.

Note: Still waiting for build (12/7/22) + delivery.

 

[jareza]

I have had the fantasy of upgrading to one of those collapsible spare tires. The ones found on Porshe or Pacifica.
I have not done my research but my train of thought is to use the spare tire space to fit a smaller tire and have some extra space.....
just a thought
Collapsible Expanding Spare Tire (wheel) - HOW DOES IT WORK??? - YouTube

 

[Scottyg77]

I have a spare tire from a rav4 prime along with tires from a highlander (235/55/20). I know that the spare from the rav4 prime will not fit in the spare tire option, it saves me money from adding that to my car (awd w/ ottomans). I have the spare in a tire wrap cover and just throw it on when we take long trips. I do not bother on around town trips.

 

[shenns]

While researching and comparing Spare Tire (Donut) sizing to full size 235/50 R20 (Width=Don't Care, Diameter=29.3").

Using Tire Size Calculator, I've come up with 4 options:
Stock: Spare tire is 155/80 R17 (Baseline: 6.1" width, 2.5" smaller diameter compared to Fullsize)
Option 1: Upgrade to 155/90 R17 (Same width (6.1"), 1.3" smaller)
Option 2: Upgrade to 165/90 R17 (0.4" wider, 0.6" smaller)
Option 3: Upgrade Spare tire set with new rim 165/85R18 (0.4" wider, 0.3" smaller, new rim +$$)
Option 4: Upgrade Spare tire set with new rim 155/90R18 (Same width, 0.3" smaller, new rim +$$)

Any and all the above is dependent of Spare tire well fitting. Maybe I can ditch the original hard cover for an oversized shower cap.

Has anyone done this or thought of doing this? What would be a good practical method of checking fitment? There appears to be about one inch around the circumference.

Also to consider, if inflated to 60 PSI, how much diameter does that increase vs non-inflated. I say non-inflated because I typically carry a portable air inflator.

Note: Still waiting for build (12/7/22) + delivery.

View attachment 59940

View attachment 59941

I also asked the same questions in the other spare thread. I just dont have room /time right now to pull off a wheel. The allure of the spare upgrade has worn off on my as I realize how much better a full size spare is. From the pictures there seems to be enough room to accommodate 30inches(i have a xse 20in). So about 1.5 inches on each side of that spare compartment.
On long trips i don't mind leaving the cover off if the tire width juts out, which it will. I got my xse last week, maybe I'll have time to try it next week.

 

[Richard E]

I also asked the same questions in the other spare thread. I just dont have room /time right now to pull off a wheel. The allure of the spare upgrade has worn off on my as I realize how much better a full size spare is. From the pictures there seems to be enough room to accommodate 30inches(i have a xse 20in). So about 1.5 inches on each side of that spare compartment.
On long trips i don't mind leaving the cover off if the tire width juts out, which it will. I got my xse last week, maybe I'll have time to try it next week.

Now that would be something- fitting a deflated full size spare in the side compartment, even if it sticks out. I’d buy the parts and do that for road trips. I have the XLE stock wheels- anybody with a spare tire compartment want to see if one will go in?

 

[Templeton]

Now that would be something- fitting a deflated full size spare in the side compartment, even if it sticks out. I’d do that for road trips. I have the XLE stock wheels- anybody want to see if one will go in?

But a thing to consider, full size spares are still huge when fully deflated. Seems unlikely that it would get small enough to fit. But, who knows?

 

[Goolong]

I ended up using a modern spare with with 27.7 inch diameter. It fits in in the location after i did the spare compartment install.

 

[pamhar]

I ended up using a modern spare with with 27.7 inch diameter. It fits in in the location after i did the spare compartment install.

So the modern spare fits in compact spare space but can not put cover on or were pics just to show how it fits?

Think the Sienna is going to give the Civic or GTI some competition when it comes to user mods!!

 

[Goolong]

So the modern spare fits in compact spare space but can not put cover on or were pics just to show how it fits?

Think the Sienna is going to give the Civic or GTI some competition when it comes to user mods!!

It fits and the cover closes over.

 

[Richard E]

I ended up using a modern spare with with 27.7 inch diameter. It fits in in the location after i did the spare compartment install. View attachment 59966
View attachment 59964
View attachment 59963
View attachment 59965

Thank you. It looks like there’s no way a 29” diameter regular tire would wedge in there, even without the cover, unless it really shrinks down when deflated.

Anybody know the diameter of the Toyota OEM space saver spare?

 

[Goolong]

Thank you. It looks like there’s no way a 29” diameter regular tire would wedge in there, even without the cover, unless it really shrinks down when deflated.

Anybody know the diameter of the Toyota OEM space saver spare?

I think the oem size is 26.8 for their spare.

 

[shenns]

I think the oem size is 26.8 for their spare.

Oh wow that's small. The XSE FWD 20inch wheels/tire is around 29in. Not good to ride on a smaller wheel for long distances , especially if you are stuck in the middle of nowhere.

 

[Goolong]

Oh wow that's small. The XSE FWD 20inch wheels/tire is around 29in. Not good to ride on a smaller wheel for long distances , especially if you are stuck in the middle of nowhere.

That's why i went with the modern spare at 27.7 inches. I plan on increasing my tires to 30" so i wanted something as large as possible while fitting in the spare compartment. Also the modern spare is rated for higher speeds so should be a bit more durable.