Spare Tire (part 2)

[tazwing48]

Re: Spare Tire (part 2)

The 225/50x17 tire I have has load rating of 1433# at 44 psi,the tire on the car have a load rating of 1521 at 44 psi. The 205/55x17 tire is 1/2 shorter than the spare it will replace,the 215/55x17 is still shorter than the spare. The 225/50x17 is the only one that can the closest to the height of the spare. I have ran tire in the past on narrower rims than are called for,the only trouble I had was the centers wore out before the edges did.But there again it is just a spare tire to get you to the next town for repairs.

Taz

[5bird7]

Re: Spare Tire (part 2)

Probably no one tried it as a source for the spares that fit the spare rim was found. So far, the only problem tires seem to have been the Firestone tires on the 02 spare rims, not the MAXXIMs found on the 03 and newer tbirds spares.

[merlot4]

Re: Spare Tire (part 2)

Paul, from an earlier thread my measurements were based on measured height from original spare to trunk liner to be 1 1/2 inches. Using the 185 spare tire, which is width in mm, that would be 7.28 inches wide; the standard tire is 235 50 17, or 235mm wide which is 9.25 inches wide;a 205 tire would be 8.07 inches (205) wide;a 215 tire would be 8.46 inches (215) wide, and a 225 would be 8.86 inches (225mm) wide.
If there is 1 1/2 inches of room to spare (sorry, I couldn't resist) that would add up to 8.78 inches, or 223mm for the compact spare width plus the space above it. So Paul, I agree that would work although it might be a bit tight. A rim that will fit, as I recall, is available and, as you say, would be preferable to the limited action spare. This thread goes back at least to last year, but I don't recall anyone trying this.

[PaulD]

Re: Spare Tire (part 2)

Typically, a 225/50x17 tire is rated for a slightly lower load than our stock tire but that should not be an issue for short term use as a spare. However, it may need to be inflated above normal air pressure to achieve that load capacity which brings us back to the issue of a high pressure spare. My main concern would be the rim width. That size tire is typically designed for a 6" or more rim. Mounting it on a 5" rim would cause abnormal wear ..... but who cares on a spare.
Another variation on this approach is a 205/55x17 tire. Has similar load capacity but is typically designed for a 5.5" or more rim. It is also slightly slimmer in width but that does not sound like an issue if the 225/50x17 fits OK.
After looking more closely at this myself, the main result here from my point of view is...
1) A 205/55x17 or 225/50x17 tire will fit on our spare tire rim and provide sufficient capability as a spare in the event our spare tire blows out. On a road trip, it should be easy to locate a used tire in these sizes and keep on going.
2) The stock spare tire has a 50 MPH speed restrictions. Using one of the above tires should allow you to at least drive the speed limit when it is mounted.
I do not plan to replace my spare tire anytime soon but it is good to know these options exist while I am traveling away from home.

Taz.....what is the load and air pressure info on the sidewall?

Update....as I searched more, I found a Yokohama 205/50x17 tire that was actually rated to fit on a 5.5" rim. Bottom line....not all tires have same rating even where they are a common size.

[AZTB]

Re: Spare Tire (part 2)

I think you may onto something, Taz...thanks for the post...let's see how our panel of experts respond.

[tazwing48]

I went an bought a used 225/50x17 tire. It mounted on my 5" spare rim ok.It also fits in the spare tie wheel well and the cover goes on top of with out hitting the tire. So this could be the answer to the spare tire problem.

Taz