Will fitting slightly smaller winter tyres on my car affect it?

I have some wheels from my 2006 Nissan X-Trail - 215/60 R17 with winter tyres that I swap on and off. My new 2014 X-Trail has 225/55 R18. There's a small difference in the size but does it matter (especially if it's the rear wheels)

Asked on 25 July 2017 by R

Answered by Honest John
If the X-Trail is 4WD then all of the wheels and tyres need to be the same size and type and within 2mm of the same amount of wear otherwise this will throw the AWD system into confusion and will damage it. Also, never ever, put cold weather or all weather tyres only on the driven wheels of a car. They must be fitted to all four wheels otherwise, in extreme conditions, the car could come off the road.
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