I am getting a car with tire size P225/50R17. I have mounted snow tires of size P205/50R17. Can I use the old snow tires/rims on the new car?
No.
That would be going down in load carrying capacity, which increases the risk of a load related tire failure, which sometimes has tragic rsults.
If the rims fit and the tires are in good condition, I don’t see why not.
“Why not” is because of a probable reduction in load carrying capacity, as noted by our resident tire expert, Capri Racer. I would strongly suggest that the OP rethink this idea, or at least that he/she compare load ratings of the two tires.
And then, there is the issue of whether the rims from the old car will be compatible with the new car. Just because both rims are 17", that does not necessarily mean that the wheel offset and the bolt pattern will be identical.
I agree with CapriRacer and VDC and all of their points. This is a bad idea.
Your tires are among the single most important safety items you have on your car. They withstand extreme impact under sometimes severe conditions. It isn’t worth compromising in this area to save a lousy few hundred bucks.
“This is a bad idea”
But asking about it is a terrific idea.
Amen to that. If more people would ask questions like this there’d be fewer unsafe cars on the road.
One other reason not to do it: the snow tires are smaller in diameter, decreasing ground clearance, not something you want to do in winter.