For the 17" hub, it's 225/65/R17. Not sure about the 16" or 18" hubs.
The 2006 Toyota Highlander has a V6 engine.
The 2006 Toyota Highlander-Hybrid has a V6 engine.
The 2006 Toyota Highlander-Hybrid has a 3.3 L base engine size.
Toyota recommends 225/70R16 size tires.
The 2006 Toyota Highlander has a 3.3 L base engine size.
225 70 16
Yes, it comes from the factory with a full size spare and wheel rim identical to the ones on the 4 road tires.
215 55R 17
The 2008 Toyota Highlander has a V6 engine.
The 2010 Toyota Highlander has a 2.7 L base engine size.
The 2009 Toyota Highlander has a 2.7 L base engine size.
The 2001 Toyota Highlander has a 2.4 L base engine size.