murdured530i

to make a long story short i ordered some tires off ebay continental extreme contact dws 235/35/18 for my new rims and they are about an inch and half smaller than my 225/50/17 on my stock rims. It looks like a huge wheel gap when i put one on the car so i took it off. I dont want to lower and lose the ride quality. Car is stock suspension non sport 2006 530i. Will these be ok or should i try to sell them and get 225 235 245/45/18 tires. the rims are 18 by 8.5 with +20mm offset. thanks in advance