Temporary spare/donut instead of the full sized spare (Yes it can be done)

[Chilezen]

I want to "pack light" and carry a temporary spare tire in my trunk. Since BMW didn't make one, from what car can I take one? Miata? Civic?
Thanks.

[Panici]

Late 90s civics have a smaller centerbore (by about 1mm), so those are out. The same can be said with early 90s miatas.


In addition to centerbore, I imagine having the same outside diameter would be important for drivability. Or even a requirement if you car has an LSD.

[roguetoaster]

I sincerely doubt that you will get much weight savings from the swap, but a VW A2 donut should fit fine and should be a direct fitment.

[Chilezen]

Late 90s civics have a smaller centerbore (by about 1mm), so those are out. The same can be said with early 90s miatas.
In addition to centerbore, I imagine having the same outside diameter would be important for drivability. Or even a requirement if you car has an LSD.

Dang, that would have real easy to find in a junkyard.

I sincerely doubt that you will get much weight savings from the swap, but a VW A2 donut should fit fine and should be a direct fitment.

The thing is, I already "tucked" my spare wheel well up into the trunk, cutting it in half and pushing it upwards. I did that for the aesthetic since my '87 doesn't have a rear apron. I didn't like the look of that bulge hanging down. That's basically the real reason. I need a spare that fits in the smaller space.
I've never heard of an A2... looks like it's a Jetta over here. Would you confirm that the year range I should look for is 1984–1992? Thanks.

[roguetoaster]

Yes, 83 or 84 to ~1992. The A3 (also called Mk3) Jetta/Bora/Golf also has the same 57mm CB and 4x100 pattern IIRC, and that platform ran to maybe 1998. Heck, even the first generation Golf might be the same, but I'm not sure those had space savers.

[uturn]

My car came with an air pump and a can of fix-a-flat.

[Northern]

I stopped carrying a spare in my e30 years ago. I just have a plug kit and a decent 12V pump now. The tire was ancient, but I think I took it out for an autox and never reinstalled it.

I'd be interested in carrying something like a donut though.

[Chilezen]

There's a Jetta and an E30 at my junkyard, so I'll go this weekend and grab the spare and test it on the car before buying. Sweet deal

[roguetoaster]

There's a Jetta and an E30 at my junkyard, so I'll go this weekend and grab the spare and test it on the car before buying. Sweet deal

Dang, I remember those days when there were multiple 80s German cars in the same yard around me.

[Panici]

The thing is, I already "tucked" my spare wheel well up into the trunk, cutting it in half and pushing it upwards. I did that for the aesthetic since my '87 doesn't have a rear apron. I didn't like the look of that bulge hanging down. That's basically the real reason. I need a spare that fits in the smaller space.

Ah the truth comes out!

Let us know how it fits.

[Chilezen]

Results:



I mounted it on the junkyard car. So obviously it's not sitting at ride height.

It fits the rear. It does not fit the front, as it hits the brake caliper.

I'm gonna go ahead and assume only an idiot would put it on backwards. Please confirm.

So because it technically fits, I bought it. $20.

Not done yet though! It needs a new tire.

I looked at what tires are available, in what sizes. This is the basically the only option I found:

https://www.tirerack.com/tires/tires.jsp?tireMake=Pirelli&tireModel=Spare+Tyre&partnum=38MR4TEMP&i1_Qty=1

This size equates to a 2.7% difference, according to this chart:



Would you consider this to be too great of a difference for the differential to handle? For open diffs, no, but what about the LSD's? Personally I have a 3.15 Torsen, and I think the gears would allow a slip like this. But I have no actual idea. I want to 2.93 clutch type later, which I assume would certainly allow a little slip.

Does anyone know details, if this is a good call?

I'm preparing for a road trip soon, so this is a $140+ decision I'd like to make soon.
I will also buy a tire inflator to keep in the car. I like the idea of a spare as a "last resort".
Thanks guys!

[roguetoaster]

The wheel is on correctly, not sure if you can find new spare tires alone, and at under 3% any diff should be okay for a short time, but I base that on conjecture alone.

[Chilezen]

not sure if you can find new spare tires alone,

What do you mean? I linked to one above. Here: https://www.tirerack.com/tires/tires...4TEMP&i1_Qty=1

[roguetoaster]

What do you mean? I linked to one above. Here: https://www.tirerack.com/tires/tires...4TEMP&i1_Qty=1

Woah, missed that neat that you can find them for sale!

[Chilezen]

Update: Pictures!