Why is my navigation drawer empty?

Will tire size affect Toyota navigation system?

• My 2007 Sienna AWD Limited came with 225/60R17 tires. If I use 215/65R16 for winter tires, will this affect the Navigation System? Should I activate the Navigation System's 'Tire Change Calibration' when I switch to or from these tires? Perhaps the GPS data will correct (or ignore) the distance traveled (wheel rotation related) data, or maybe it wont? Is the wheel rotation data only used when GPS signals are unavailable or poor? The stock tires of 2007 Siennas (as well as other years) are either 225/60R17 (the size of my all seasons) or 215/65R16 (the size of winter tires I'm considering). Is the Navigation System available on Siennas with 215/65R16 tires? Has anyone with a Navigation System changed tire sizes? If so, any adverse affects? Anyone know what the 'Navigation: Calibration - Adjust - Tire Change' does? Is it supposed to be used to adjust from a worn tread to brand new tires of the same size, or will some GPS distance measurement be used to determine the circumference of the new tires (possibly of a different size)? I've talked to service staff at a few Toyota dealerships, but can't a a straight answer from anyone. If I used 225/60R17 winter tires & rims I wouldn't need to worry about any Navigation System side-affects. But since no 17" steel Toyota rims are made for Siennas, I must resort to 16" steel Toyota rims, or use non-Toyota steel rims (I don't want to pay big $s for a second set of alloy rims) but then there would be the whole hub-centric issue with which to deal ... (BTW, I am aware of the issues regarding the direct tire pressure monitoring system and a new set of wheels, and that my odometer and speedometer will report slightly inaccurate readings.)

• Answer:

  Your gps/nav uses a locator sensor in the van to provide your location. Tire size has little to do with it. It will effect it slightly if you are in a "blind" spot as your gps system will use your speed and direction to guide you, but once your locator picks up again it will automatically correct itself.