Before modifying your wheels, you should read page 180-181 of your owners manual:
The warning in bold states:
Improper accessories or modifications can affect your vehicles handling, stability, and performance, and cause a crash which you can be hurt or killed.
Follow all instructions in this owners manual regarding accessories and modifications.
Specific examples of what not to do are listed on page 181:
Lowering the vehicle with a non-Honda suspension kit that signicantly reduces round clearance can allow the undercarriage to hit speed bumps or other raised objects which could cause the airbags to deploy.
Raising your vehicle with a non-Honda suspension lit can affect the handling and stability.
Non-Honda wheels, because they are a universal design, can cause excessive stress on suspension components and will not be compatible with the tire pressure monitoring system.
Larger or smaller wheels can interfere with the operation of your vehicles antilock brakes and other systems.
Modifying your steering wheel or any other part of your vehicle’s safety system could make the systems ineffective.
The Ridgeline’s tires and wheels were specifically designed to meet the load rating, handling, and crash performance of this vehicle. Any aftermarket wheel will not meet the strength requirements these wheels have been subjected to. Therefore it is an exceedingly bad idea to replace them with ANYTHING other than the Honda accessory wheel. Additionally, you should be aware making this type of modification voids any warranty claim relating to the suspension, brakes or drivetrain. Proceed with caution.
Increasing the tire diameter changes the radius of the wheel which in effect changes the gear ratio. This will have a significant negative affect on the launch performance of your vehicle and is therefore ill advised.
Changing the off-set or width of the wheel significantly affects the load inputs into the suspension and wheel bearings. Again, altering the geometry of the suspension in this fashion is ill advised.
Finally, the tire was specifically developed to meet the on-road, off-road, snow performance, NVH level, and load capacity for this vehicle. If you change the tire to an alternate design, make sure the load index rating is an equivalent number (=105). This modification will significantly affect the ability to maintain safe and confident handling when your Ridgeline is loaded.