Left front tire blow out. Due for new tires and decided on decent used matching set. Drive home had vibration like balance. Technician said the wheel was not damaged. Also noted the size difference after I get home. 2004 Toyota Sienna 2WD Is there any easy way to determine if it's the tires or a damaged rim? Note rims are original equipment aluminum.
Useful resource here on tire sizes:
But the smaller tires are only slightly narrower and less than 1" smaller radius. So I very much doubt that is the source of your vibration. The only real downside is that these will cause your speedo to read a bit high and your engine to turn a bit faster at the same actual speed.
I'd have the balance checked, check the tires for out-of-round (they were used for a reason), and also check the wheel for damage and runout.