Is it advisable to replace the 16.5-inch rims on a model GMC motorhome with 16-inch rims?

No, it is not advisable to replace the 16.5-inch rims on a model GMC motorhome with 16-inch rims. Doing so will most likely make the tire sidewalls bulge out more, as 16.5-inch tires have higher aspect ratios than 16-inch tires. This can lead to premature tire wear and potential safety concerns.

Plus, switching to a smaller rim size may void manufacturer warranties, affect speedometer accuracy, and impact vehicle handling by altering ride height and suspension dynamics. In summary, it is generally discouraged to change automotive parts from factory specifications unless recommended by experts for very specific considerations that outweigh the possible risks.