I have a 2004 Subaru Impreza WRX, but I suspect my question can be generalized to apply to many smaller cars.

Not being a fan of donut spare tires, when I replaced my tires about a year ago I kept the one that was in the best shape, mounted on a used steel rim that the shop sold me for cheap.

Much to my chagrin, the now full-sized spare does not fit in the well designed for the donut, so it's taking up space in my trunk (and sliding around a bit despite the bungees). I have researched kits for mounting the tire, but haven't found anything suitable for my car. Is there any solution so I can have a full-sized spare and still have my trunk space?

5 Answers 5


I only see three options.

  1. Modify the hole where the spare tire goes, read cut and weld in a new one if there is room

  2. Find a way to mount it outside the trunk, like under the car, doubtful that this could be done.

  3. See if you can get the tire un-inflated in the same space, my 1991 Camaro came from the factory with an un-inflated spare, and a can of what looks like fix a flat that you use to inflate the tire before you put it on, making it smaller to store.

I don't think it will be worth the hassle, either give up the trunk space for the full size, or put the doughnut back in.

  • I had thought of mounting it on the back, but I'm not sure I can do this without blocking the plate. I might have to mount the plate on the spare. Either way, it'd probably be unsightly.
    – kojiro
    Commented Mar 19, 2011 at 22:55
  • @Larry - I don't think Fix-A-Flat is enough air to fully inflate a deflated tire. I think fix-a-flat is designed to inject material that, when you drive the vehicle, will use the concepts of centrifugal forces to push the material to the outside of the tire, filling in and sealing any leaks. Do you have information that demonstrates how low a tire can be in order for that method to work?
    – jmort253
    Commented Mar 19, 2011 at 23:32
  • @Larry, I tend to agree - I carry a donut and fix a flat in my car. If the hole is small, the can will get me to the tire shop. If the hole is big, it's time for the donut.
    – Bob Cross
    Commented Mar 20, 2011 at 1:28
  • 4
    @kojiro I would recommend an alternative. Keep the full size spare at home and the donut in the car with a can of fix-a-flat. Either the donut or fix-a-flat will get you to a mechanic/home and you don't have to worry about your trunk space. But if you are going off-road or somewhere there is a high likelihood of getting a flat, throw the full size in the trunk.
    – Patrick
    Commented Mar 21, 2011 at 21:23
  • 1
    @kojiro another option would be to build a small box out of wood or thin metal that will hold the tire in place in the trunk. You could also carpet it to match the interior. If it can't be perfect, at least you can look good doing it :-)
    – Patrick
    Commented Mar 22, 2011 at 2:20

Recently I've helped a friend with the same problem. We created a double bottom with, and attached the top with hinges so you can open it. The cover has 4 bolts on it (the car uses 4x100 rims) and attached the spare to the bolts. When you open the cover you can use the spare and the well is available to store stuff like the jack and some other tools. Also, because the spare is mounted directly above the well there's no heavy object lying on one side of the boot affecting the handling of the car.

Please keep note that carrying a spare the same size as the normal wheels is important. Mounting a smaller spare on a driving axle can lead to overheating of the differentials. Normally on a 2-wheel drive you can swap a good wheel from the other axle to the driving axle to avoid this, but that's not an option on a 4WD Subaru.

  • Thanks, Alex. What I've been told is that the different tread depth on the spare versus the other 3 is also likely to cause the differential some wear, but I can't imagine it's worse than would be caused by the donut. So anyway, with this approach it sounds like I would have to sacrifice some vertical space, but I'd gain stability and it'd look better. Does that sound about right?
    – kojiro
    Commented Mar 20, 2011 at 16:04
  • Stability will be better compared to a tire on one side of the boot, but worse compared to a donut in the well because of the higher centre of gravity. I don't think this will be an issue on normal roads en on the track you'll leave the spare at home anyway so that won't be a problem. And yes, you'll lose some vertical space but you can store a lot of things (towcables, tools, jumper cables, amplifier for the ICE, etc.) underneath the double bottom so you'll get a nice and clean boot in return.
    – Alex
    Commented Mar 20, 2011 at 17:34

I can see why you don't want a donut tyre - an Impreza is for driving:-), but one of the compromises on the build means you really can't do much about the spare.

My two thoughts:

  • just accept the donut spare is necessary - it will get you to a garage to get a new tyre

and offtopic:

  • test drive a Forester STi - almost identical chassis, but a bit bigger vehicle, a bit faster, has full size tyres, handles better, accelerates better

(disclaimer - I always had Imprezas until I drove the Foz. I am now biased :-)


I put the tire in upside down and bolted it, measured how much higher it sat than the base, cut some 2x4s to support the panel and voila


Short of chopping and welding the boot floor, you could possibly create an artificial boot floor that sits higher than the existing one.

Some outside the box alternatives are;

Spare on Rear

Spare on Bonnet

Spare on Roof

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