I was wondering if a 2008 Honda Odyssey can hold a full size spare tire, or will it only fit the donut?
The easiest way forward to answer your question would be to remove one of your full size wheels and try it. You would avoid all possibility of being mislead by tyre sizes, wheel rims and the such like available across the range of your vehicle. Cans of compressed gas and sealant are available to effect a temporary repair to allow a vehicle to get to a tyre shop a lot cheaper then a full size wheel and tyre. If the concern is what would happen in the event of a puncture you may be able to take consolation in the stats available which say you will only get a puncture once every eight years. But then again it has been said that stats '...are lies, more lies and damn lies - Winston Churchill'.