Full size spare - will it fit? Also which steel Corolla wheel works?

GOOGLE it - there are lots of PriusChat threads on it - if you put PriusChat in your search query, it will target them.

 

Take one of your regular wheels off and try. I think it won’t quite fit, if it’s like third gen.

 

Just buy a used Prius wheel off of ebay. That's what I did. A spare full-sized tire method | PriusChat

Then find a reasonably priced, but OK, new tire to put on it. Put it together and put it in. LOCK IT DOWN so that it doesn't become a projectile in a crash.

You will need to build up the rear platform support around the tire to support the 'floor.'

 

Yes it will fit. I did it to my Four Touring. Here is the write-up: Installing full size spare in 2015 4-Touring | PriusChat

But the full size spare is going to be wider so it will raise the elevation of the floor in your cargo area and the Styrofoam inserts will not work. You will have to come up with an alternative.

The compact spares are the same diameter wheel but they are much narrower so they will fit into the cargo space without raising it and you can find or buy the foam inserts to fit around the spare. The main reason for going with a compact spare is to avoid raising the level of your cargo area which is more of a project and requires some sort of custom-made supports.