Pulling to one side while driving on the highway

[nightstrike]

Hi everyone,

I have a 2023 Stinger GT2.

I recently changed the tires and rims from the winter to the summer setup:
- Winter: 18 inch rims with Michelin X-Ice Snow
- Summer: OEM 19 inch staggered with Michelin Pilot Sport 4S

After making this change, I noticed that while driving the car at highway speeds (above 100 km/h), it has tendency to sometimes pull to the right and thus require a correction with the steering wheel. I did not have this issue while driving the car with the winter setup.

While changing the rims, I did not notice any significant issues with the suspension nor the rims. I did check the tire tread and I noticed that the right rear tire has around 2 mm less tread than the left rear tire. (The left rear tire was replaced by the previous owner in 2023). The front tires have around the same treads.

Could the pulling of my car to the right be caused by the unequal tire tread wear in the rear? Did anyone experience a similar issue with their Stinger?

 

[Snicklefritz]

I have had uneven tread wear over the years, nothing extreme. Remember that road camber is designed to pull the car to the right, away from opposing traffic. That's the only time I have to apply a bit of pressure to the left.

A suggested check is to make sure that all four tires show "outside" on the sidewall. I ran a couple thousand miles on a RF PS4S that was on inside out. I didn't notice anything like pulling in one direction or any other handling issues, so, probably that wouldn't pull to the right. But you want to mount the tires as designed.

 

[Thomby]

it has tendency to sometimes pull to the right and thus require a correction
right rear tire has around 2 mm less tread than the left rear

As @Snicklefritz mentioned, the crown of the road will lead your car slightly right but it shouldn't be too severe. I'd always thought it was just for drainage, but it appears even divided highways will have a single slope per side (high on inside toward median), versus separate crowns with high centers like a two lane, so cars will always tend to drift to the outside.

As a test, just swap the rears and see if it cancels out or reverses.

 

[nightstrike]

Thank you @Snicklefritz and @Thomby, I appreciate it. Yes indeed all four tires show "outside" on the sidewall.

 

[D.J.]

In my experience, winter tires with softer sidewalls and flexible tread blocks, are less prone/susceptible to the effects of road crown when compared to cock stiff ultra high performance summer tires.

It is not surprising at all to hear that you feel the effects of road crown more with summers vs winters.

 

[Ah GetFd]

Turn off the Lane Keeping.

I found that was pulling my MY23 GT to the left on RHD roads.

Now drives straight as a die