I have 225/65R17 winter tires, but want to put on 225/65R16 instead, as they are mostly available. Please inform me of the consequences of doing this. I have a 2013 RAV4 Limited.
First you need to check whether 16" wheels will fit onto your vehicle - there's a minimum diameter needed that will clear the brake calipers and maybe ball joints. Often, some wheel styles in the minimum size for the vehicle will fit, and others won't, depending on the geometry of the rim 'barrel' and the shape of the spokes.
Once you've found whether the 16" wheels will fit, the 225/65R16 are 0.5" smaller in rolling radius, so you lose that from your ground clearance, and your speedo will read high by about 3.5%. 225/70R16 is almost exactly the same size as the 225/65R17 if you can find those.