So last night on of my friends gave me a toyo proxe tyre in 225 45 17. I belive this is the size people turn to because they are cheaper. My questions are can I use it as a spare even though I have 205 50 all round? If I was to fit it to the car will it rub? Im on standard spiders with ap coilovers fronts wound all the way down so about -50mm.

I'm on 225/45/17 and got no rubbing and if you stand them next to a 205/50/17 won't notice much difference

Are u lowered? Am I ok with it as a spare? My concern is the rest of the tyres are a different size.

It will be fine as a spare in an emergency

But cannot be used as an everyday tyre as you must have the same sized tyres on the same axle