Problems with Spare Tire

[braumeister]

My class B has a full size spare tire too, mounted on one of the back doors. When I purchased it, all the tires were about 9 years old. I immediately replaced the 4 that were on the vehicle, but left the existing spare on the back. Now I'm wondering at what point I should purchase a new replacement for the spare. Sometime this year, that 9 year old spare will turn into a 10 year old spare. I'm thinking that even for a spare tire, 10 years is too old. I should be able to get a replacement for ~$150. If ever caught by a flat in a remote area with no cell reception, I'll be happy for a good spare. That $150 will, at that point, feel like money well spent.

The rule of thumb is that tires should be replaced by the time they are six years old, regardless of wear.

Tires Expire in Six Years - Tire Safety Group

 

[TromboneAl]

Yeah, try it with just the velcro on the tires and if it adheres well to the carpet then declare victory.

Done. Works great. The Velcro strips also indication which lug holes to use (assuming I remember that when I get a flat).

 

[TromboneAl]

The rule of thumb is that tires should be replaced by the time they are six years old, regardless of wear.

Tires Expire in Six Years - Tire Safety Group

"Sunlight, heat, ice, and general wear and tear can accelerate the breakdown of a tire." Hopefully, the spare on the undercarriage of our Tacoma will still be usable (twenty years old).

 

[braumeister]

"Sunlight, heat, ice, and general wear and tear can accelerate the breakdown of a tire." Hopefully, the spare on the undercarriage of our Tacoma will still be usable (twenty years old).

From the link I cited:

The tire aging process happens regardless of whether a tire is on a vehicle or in a temperature-controlled room

Over time, the tire will simply fall apart under normal stress, just like an old rubber band. Because this process occurs naturally, it does not matter if a tire is being used, stored as a spare, or simply waiting on a store shelf for an unsuspecting consumer

 

[TromboneAl]

I was afraid of that.

 

[nwsteve]

My class B has a full size spare tire too, mounted on one of the back doors. When I purchased it, all the tires were about 9 years old. I immediately replaced the 4 that were on the vehicle, but left the existing spare on the back. Now I'm wondering at what point I should purchase a new replacement for the spare. Sometime this year, that 9 year old spare will turn into a 10 year old spare. I'm thinking that even for a spare tire, 10 years is too old. I should be able to get a replacement for ~$150. If ever caught by a flat in a remote area with no cell reception, I'll be happy for a good spare. That $150 will, at that point, feel like money well spent.

We solved your issue on our class B by rotating the best tire of the lot when doing tire replacement to "old" spare position. We replace our tires approx. when top of head on quarter is visible so plenty of tread for a spare. If going into winter, will even do early for safety and traction over winter.

We had our B, 10 years and 95k miles, and good fortune never had a flat.

 

[GrayHare]

Done. Works great. The Velcro strips also indication which lug holes to use (assuming I remember that when I get a flat).

I don't know the interior design of your vehicle, but if that tire shares space with the passenger compartment you'll want to secure it more tightly than velcro so it does not become a decapitating projectile upon a front end collision.

 

[NW-Bound]

Many cars have tie points inside the trunk to aid in securing cargo. If Tesla cars have those, a chain or steel rope can be used to secure the spare tire.

 

[pb4uski]

I don't know the interior design of your vehicle, but if that tire shares space with the passenger compartment you'll want to secure it more tightly than velcro so it does not become a decapitating projectile upon a front end collision.

Great point. Should anticipate what it might do in a collision.

 

[Jerry1]

Great point. Should anticipate what it might do in a collision.

Learned that the hard way. As a kid, I had some stereo speakers jus sitting on my back window deck. They snugged in there well enough that they didn’t move around. Then, I rear ended someone. Those speakers came flying all the way up to the front of the car. Lucky my injuries were minor and none from the speakers, but it taught me a lesson.

In the Tesla, is there some structure behind the seat, or, are they fold down with a pass through to the cabin? If a pass through, that tire needs to be booted down tight. A strap around it is not good enough. It will allow the tire to start moving and momentum could force it loose or break whatever tie down is being used. Will the spare fit in the front (frunk?)?

 

[TromboneAl]

I don't know the interior design of your vehicle, but if that tire shares space with the passenger compartment you'll want to secure it more tightly than velcro so it does not become a decapitating projectile upon a front end collision.

In the Leaf, I strapped the spare to a solid hold-down eyebolt. There is no such bolt in the Tesla.

The trunk is separated from the passenger compartment by fold-down seats and a solid "ceiling."

One guy hung his spare from that ceiling.

The tire will not fit in the frunk.

I brought up this same issue to someone who said he kept the spare in the footwell behind the driver's seat. He was wrongly confident it would stay put.

 

[TromboneAl]

Yeah, try it with just the velcro on the tires and if it adheres well to the carpet then declare victory.

Around the ten-second mark of this video, you can hear the spare sliding forward and banging into the back of the rear seat (pre-Velcro):

https://photos.app.goo.gl/ZQMSa5Vhsb2XwHEQ6

 

[ShokWaveRider]

I have a similar problem..... Sorry I could not resist....

 

[aja8888]

Al, consider a roof rack. Put the tire on it for trips.

 

[MRG]

Al, consider a roof rack. Put the tire on it for trips.

Now we know why it didn't have a spare. Jeep announced they're going to have an EV Wrangler in 2022, they have a spare tire.[emoji41]

 

[pb4uski]

Al, consider a roof rack. Put the tire on it for trips.

 

[Jerry1]

I assume the seats have latches that are reasonably substantial. Put the tire up against the seat backs so that they don’t pick up momentum in a crash. Some sort of wedge to hold it down might be helpful too. Of course bolting it down would be best, but in the absence of that, at least stabilize it as much as possible and snug it up against the strongest part of the seat backs. There comes a point where you have to acknowledge that if you’re in a crash that sends the tire crashing through the seat backs, you’re going to have a bad day no matter what that spare does.

 

[Gearhead Jim]

The rule of thumb is that tires should be replaced by the time they are six years old, regardless of wear.

Tires Expire in Six Years - Tire Safety Group

Michelin says tires should be inspected after five years and definitely discarded after 10 years. Every manufacturer seems to have different standards.

I think the inspection is adequate if it's done every year after 5 years, and is a really careful look all over, not just a glance.

 

[Gearhead Jim]

Another issue with spare tires are with the drive axles. If a vehicle has a limited slip drive axle(s), the tires must be the same exact size. If not, you may burn out the limited slip in the differential. I have no idea what Tesla's axles are mechanically like.

Notice how Jeep owners have 5 equal size tires on them? That's why.

Many cars now days have a donut spare that's smaller than normal, or a runflat tire will have a somewhat smaller diameter when flat. Surely, some of these cars have limited slip (like our 2017 Corvette). And of course the differential does some slipping every time you go around a corner. So some amount of difference for some length of travel must be ok.
But it's hard to find out how much.

If your car has the same diameter tires on all corners and typically has limited slip only on the rear, you could swap around so that two of the good tires are on the limited slip axle and the reduced diameter (donut/runflat/oddball) tire is on the other. Kind of a PITA to do that, but should work ok.