I'm getting ready to order MIchelon PS2's for my car
But just last week I rotated the tires front to back
This made a big difference when driving at higher speeds, 60 thru 100 mph, anything below 40 mph the car
just goes were it wants and feels real unstable.
Before I rotated the tires I did have the wheels balanced and aligned ( surprising there wasn't much adjustment needed )
Would a rebalnce help the lower sppeds or are the Bridgestone RFT
( 225/40/17 made for performance at highjer sppeds rather than lower speeds

I'm getting ready to order MIchelon PS2's for my car
But just last week I rotated the tires front to back
This made a big difference when driving at higher speeds, 60 thru 100 mph, anything below 40 mph the car
just goes were it wants and feels real unstable.
Before I rotated the tires I did have the wheels balanced and aligned ( surprising there wasn't much adjustment needed )
Would a rebalnce help the lower sppeds or are the Bridgestone RFT
( 225/40/17 made for performance at highjer sppeds rather than lower speeds

Correct me if I am wrong, but aren't the front and rears different sizes?

Only with the Sport Suspension.

not always different sizes with the sport package. My 03 has 17" 235's all around.

DMSZ4 has a Z4 which always come with different sizes front to back.

Most likely the problem your having is because of the run flats. Michelins have always been great tires for anyone I've known that has them, including me.

It's all the runflats' fault. Report back here when you get your PS2's. I'll bet a year's salary that you'll be ecstatic and urging everyone suffering on runflats to get rid of them, wishing you'd done it sooner, etc. Happens EVERY single time someone switches, yet some people will still defend these turds. I've been through the switch on an E90 330i, and believe me, it turns the beast into a different animal altogether. You'll be very pleased. :alright:

One the one hand you are definitely going to like the PS2's when you get them on, but I am going to go against the grain here and recommend that you do not rotate your tires on the Z4.

The negative camber for the rear tires is considerably higher than what is dialed in up front and the wear differences between the front and rear will definitely leave your car feeling somewhat hard to steer. I made this mistake with my winter tires after I yanked them off for a track event and didn't pay attention to where they came from. I ended up pulling all 4 wheels back off and on careful inspection I found that I could identify which wheel had been at which location by the distinctive wear patterns. The rears showed a lot more wear on the inside shoulder and almost none on the outside where the fronts were much more uniform.

The squirrely feeling in the steering went away immediately once I had the tires back to their original positions. The tires in question here are 225R45/17 non RFT Pirelli Wintersport Sotozeros.

Is the suspension setup the same for the Sport as for the non-Sport? When I replaced the tires on my 2006 3.0i Roadster, the rear tires were worn evenly across the tread. It does not look like there is more camber on the rears, at least to my eye. Thanks.