I just picked up my first MINI about ten days ago and am LOVING it so far. I mean REAALLLLYYY loving it. One thing that is a little unsettling is a slight rocking back and forth that I experience ONLY at freeway speed. The back end of the car feels like it is shifting side to side. It is very consistent. As soon as I go above 65 I feel it. I never feel it below that speed. I've driven fairly aggressively through mountain twisties at slower speed and do not feel any instability in the suspension at all. It grips like mad. I just had new wheels and low profile tires put on this afternoon and now notice the wobble is slightly more pronounced so I now know it had nothing to do with the stiff sidewall runflats. I don't remember feeling this at all during the test drives. Has anyone else experienced this or have any idea if it is anything I should address with service?

 

It may the new tires tracking the rain grooves of the road. You'll most likely need to switch tires to a different tread design to get rid of it, if that's the case.

 

You are tramlining on the highway grooves. Common with runflats and some non runflat tires. Usually concrete surfaces not all the time but in some areas.

Don't drive there anymore, go the long way around and enjoy the view.

Stick to smooth black top roads for best results.

 

If it is tramlining, check your tire pressure. The manual has a guide for what you usually carry int the car (one or two passengers, luggage or no luggage). If the tires are inflated higher the tramlining will be more noticable. I brought mine down to the "under 100 MPG, two passenger, no luggage" setting and handling improved too.

 

"under 100 mph" I think

 

I believe you are right! I was paying attention this morning and it was only happening on certain freeway surfaces.

I could definitely take the long way and turn the 10 minute freeway commute into a half hour twisty mountain road commute

 

That sort of "groove tracking" is very familiar to motorcyclists, and tends to vary based on the tread pattern on the tires. (some tires are much more prone to it than others) How distressing that MINI's have to suffer from the same "nervous handling" disorder!