Hello All,
I’m new to the site but not new to Nissan/ Infiniti. I currently own a 2008 G37 Coupe Journey model. I recently had to change my tires be the ones I had were worn out. My problem is I’m running 245/40R19 all around because I wanted to have the opportunity to rotate my tires when needed. This is where the problem has started I got all 4 brand new tires along with a 4 wheel alignment. The problems I’m having are at high speed between 60-80mph my steering wheel starts to shake not a lot but noticeable it wasn’t doing that before. I’m just wondering if it’s because I went with the same size tire all around and in the front I didn’t put the recommended 225/45r19. Any advise would be helpful. Or if anyone had this problem and what did they do to correct it. Thanks guys!

The issue is related to tires or balancing. Have them road force balanced.

If you got them balanced before, the shop didn't do it correctly.