Here is a chart I put together using user data here on the forums to show available tire sizes for the Ridge, how they fit, how far off they throw your speedometer, and what modifications you might need to squeeze them in. Please check my results and let me know about any additions/corrections. The chart is also available in PDF and XLS (Excel) versions below.
Please note that tire manufacturers often vary in exact sizes, so check questionable fitments against the actual product specs. The downloadable files have hyperlinks to reference pages for examples and instructions.
*Trunk is approximately 275mm tall w/o the tire tray, and 30.5 inches wide between the trunk hinges
**Grind welds: Requires removing the mudflaps and grinding down the vertical pinch-welds on the rear side of the front wheel wells.
*** Fender Cutting: Not for the faint of heart. It has been proven to fit, but you will have to modify the sheet metal.
note You may notice that for most applications, a lift is actually not required. Due to the shape of the front wheel wells, the available 2" suspension lift does little to add usable clearance. The tires are more limited by the width of the wheel wells from the front bumper to the mud flap.
#Warning# To date, only Honda technicians can correct your speedometer/odometer, and most are unwilling to do so. Changing tire sizes can alter your speed and mileage readings, as well as confusing the computer inputs required for speed calculations used by the VSA, VTM-4, and transmission shift points.