Can I change my wheels and tires to a different size on my car?

So my friend gave me a set of wheels and tires and rims, just because, he know they were 17s and he didn't want them. They're much better than the ones I have. I'm just wondering if I can exchange it all out. The wheels and tires he gave me are p215/50r17 and the ones I have on my car currently are p225/50r17. I don't know much about cars and how they work. Because if I can I'll switch them out out, if not I'll just pass them back. I have a saturn aura and he had a Honda civic I think. I'm not sure if that pertains to anything relevant tho.

Please and thank you guys

Yeah, you can, but not generally recommended. They are only about 10mm thinner, so you could fit the tyres on your wheels though if you really wanted too. Just as long as you change all 4 the same and not mix the two sizes

The tires are too small ( load index may be too low ) and the rims may not even fit ( wrong bolt pattern and/or incorrect offset ).

Going to a 10mm narrower tire is not a major issue as long as the tire load index and speed rating is equal to or greater than the original equipment tire. However, your major issue is if the bolt pattern and offset of the wheels are compatible.

You can fit the tyres to existing wheels on car but can't use the wheels tyres are on now… The tyres will be narrower. And not as tall

As others have noted, the tires are 10 mm narrower. They are also about 0.4 inches shorter in overall height. They will fit in the wheel well. Your speedometer and odometer will be off by about 1.5%. That said, the primary concern if the bolt pattern/offset. Not all 17" rims have the same number of bolts, and even those that do are not all the same distance from the center of the wheel.