回复：请教轮胎SIZE的问题

In theory change the OEM size 225/60R17 down to 215/60R17 is not OK or recommended. The usual recommendation is up the size to 235/55R17.

But in real life, there is no problem; the vehicle will be a little lower,since the new tires size is a little narrower and smaller. Please remember 215/60R17 is a little narrower than 225/60R17, so when the road surface is slippery, more care should be taken in handling the vehicle.