If you were i nthe US, I would say a dealer woudl do it. But, that only 3% difference. I wouldn't worry about it. At 100kph, your speedometer will read 3kph lower than you are actually traveling.

 

215 65 17 will give you a higher ground clearance. Dealer should be able to flash computer to new tire size.

 

With higher tirewall (65) youll get lower rpm at cruising speed, better mpg and less noise. (and a fraction slower - but do you care?)

Id go for the 215-65-17 if I were you.

 

How would you get less noise with a larger diameter? Wouldn't it be the other way around?

 

Lower rpm - lower noise. Road and wind noise are obiously the same. Ofcourse, the gains are only slightly. The 5% difference isnt all that much. (but something )

 

I know this is probably a dumb question but can you mount them on the same rims? Like have 215 60r17 then take them off and mount a 21565r17 on the same same rim??

 

Yes, there is no difference in rim size for those size tires.