Ok so i have an 08 Mustang, I have aftermarket 18′s on it, I recently just bought brand new NEXEN N 3000 tires which are 255,45,18, before unfortunately, I had the wrong tires on there from my previous car which were 215/40/18, VERY BAD! I was shocked to find out that my tires hadn’t blow by now with the weight of the car.. Well after I bought these new tires i went and got them balanced, my car was shaking before but now for some reason whenever i hit 45 and up my steering SHAKES LIKE NO TOMMORROW. How is this happening?!! I got new tires, the rims have hits on the lip but not anywhere else, the lugs are the stock lugs since they fit, I got the ring inside the rim so that it won’t shake.. I don’t know what to tell the tire dealers anymore. They keep balancing it and they tell me it’s ok, when I leave onto the highway there goes the problem again. It’s very awkward and because of this shaking I can hardly keep control sometimes. Sometimes when I break it feels I guess this is the best way to say it, like when you’re on a Jet ski and u feel that the jet ski is going to the side because of the waves, well in this case when I brake it feels like my car just slips to the side.. Weirdest thing………

Also when i accelerate, and its only sometimes, I feel this tick on the tires, it sounds like keys in a way just jiggling but it’s not and the faster I accelerate the more the noise happens, it’s like a rattling noise.. Does anyone know what this could be? Could this be a result of my old tires and may have affected the struts or the coils?

I am already sooo frustrated with this.

Please someone help!

Thank you so much!
I know that ive hit the rims REALLY hard in my old car which was an 06 Scion, like 3 times. Is there a way to fix that? the Dealers” supposedly” have looked at the rims and never have advised me.. =/
I would want to take it to the Ford Dealers, however they told me they once i have aftermarket tires and rims, if something happens obviously its my responsiblity, if i put the stock rims and tires back on and complain about this problem, could it be possible that the dealer will cover me under warranty? in the case that the struts or suspension are messed up? my car has only 10,000 miles since i got it last year. If someone may be able to help me with this also i would appreciate it.

Thanks
So i took my car back to the tire shop, and they told me that it could be 2 things one the HUB CENTER RINGS that are flimzzy, also the lugs i have on are the stock logs but they shouldnt cause much of a problem but its not really too much of a bad problem. they checked my alignment, the rods, and everything, and they said this car is in great conditions, however the HUB center rings could be the problem.

The tires i have now are the exact size for the rims i have which are 18X9, the 255/45/18 are the recommended size, the ones i had before which were 215/40/18 were obviously the wrong size. The tires are not rubbing on any part of the car. Does anyone have any other ideas? Maybe the Hub center ring recommendation will work, although i have all 4 rings on the rim so i dont see how they would wear but i guess you never know.

Help !! how frustrating…