so I have been looking for a donut spare for a while.
Tried the yards, but had a hard time finding one.

I found a couple of webpages that give not only the bolt pattern but the center registry hole size as well.
turns out mostly only dodge and chrysler have large enough center registry holes.

https://sizemywheels.com/lz-pcd/5-114.3/dodge/grand-caravan/38i-rs


backspacing and stuff doesn't really matter here since this is only a 4 inch wide tire and it is just to save space, I started looking for the newest stuff out there that will bolt up.
turns out the intrepid and pre-2007 dodge caravans still have the correct bolt pattern and center registry size for our old cars.

the tire size is wrong, but found one for 100 bucks that is really close to the 255 60 r15's I run. only off 1 or 2 revs for the size.

https://tiresize.com/calculator/
you can compare here.

so I was able to find a wheel for 60 bucks and can now junk the full size 20 year old spare sitting in the trunk.

even with the wheel it is cheaper than another full size tire on its own.

Good info, I found the aluminum spare rim from a Crown Vic works well too, they are 16" and very light.
Here's an Ebay for reference, I found 1 local on CL for $30 and tire size is perfect, 145/90/16
I did have to hit the center register with a file to open it up, Ford's are slightly smaller than Mopar.

https://www.ebay.com/itm/254752978805

yeah fords are like 67.1 vs 72.1 for mopar.
I thought about that, because there are a lot of other cars with the same bolt pattern but too small center regsitry's.
like hyundai and some honda's actually have the same bolt pattern. Even some newer toyota trucks.
but I couldn't see myself trying to open up that hole. or rather, I didn't see me being able to do it uniformly lol.

i have been trying to find a pair of 165-90-15's [new and identical] doughnuts to use as mockups on my eternal project, 33 dodge humpback panel truck.
i want to put these on a crusty pair of 15x4" cragar ss wheels.