LS4 Performance - 225/55/18 all around?

i just slapped on some pirelli tires 225/55/18 and after 50mph its shaking and stops after 70mph.... is the tire size the reason?

I remember that you bought your vehicle with those aftermarket wheels. Are they 7 or 8 inches wide? Did you get them balanced?

I think 225 is a little too narrow for an 8" wide wheel. Now if they're 7" you should be fine.

Small FYI: our rear tire size is 225/50-18 on a 7" wide wheel from the factory.

I remember that you bought your vehicle with those aftermarket wheels. Are they 7 or 8 inches wide? Did you get them balanced?

I think 225 is a little too narrow for an 8" wide wheel. Now if they're 7" you should be fine.

Small FYI: our rear tire size is 225/50-18 on a 7" wide wheel from the factory.

A 225/55 on an 8" wheel should be fine. Not ideal, but it shouldn't have any weird issues specifically related to tire-rim size. Years ago I ran 215 snows on 16x8's on a few different vehicles (first an '88 TA, then a '98 Z28, then a '00 Jimmy 4x4).

Oh okay. That's good to know.

Thanks!

Sounds like a balance issue. Didn't do it before, right?

If it took 50 miles for it to start happening, maybe a weight fell off? Check the sidewalls for any bulges? Check lugnut torque? I'd take it back to the tire place and have them check the balance. They'll be able to let you know if it is a balance weight issue or a tire issue (shifted band, etc.)

If balancing checks out, I'd look at how the wheels are bolting to the car to make sure there aren't any issues there.

might check and see if the aftermarket wheels have hub rings. thats what solved my problem

Ill check all these out thanks guys.

Check loose lug nuts!!!

Or it could be the tire with a bubble. Needs to be rebalanced. Maybe bent rim. Idk I'm out of ideas lol