Modern cars have very sensitive suspension geometry and fitting wheels and tyres that aren't the right size, offset or load index can noticeably affect the way a car drives at best and be actively dangerous at worst. Check these new wheels and tyres are the same width, tyre profile and speed/load rating. These are the numbers on the side of the tyre, as an example: 225 (width) / 50 (profile) R17 (17-inch wheels) 98 H (load index up to 750kg and speed rating up to 130mph).