2008 535xiAt about 80mph, the car felt real loose and unsettled today, especially in the curves of the highway. Straight line felt OK but still would get a strong "swaying" feeling at times.

I have multiple things going on to explain it away but not happy with the feeling at all.

1) Had a car full of 4 adults and trunk full of luggage loaded to the max.
2) I had to put my wife's 17" wheels with brand new all-season tires on the front and newish ones on the rear. (I had a couple bad wheels and tires that I couldn't replace in time)
3) Been upgrading my chassis and handling. Right now I have a larger M5 sway bar and pull-rods on the rear and nothing new on the front. Stock suspension.

any thoughts on something more specific than others that probably caused such a loose front end? I didn't like it all

This is the first time I have had such a full trunk of luggage so I am assuming that was my problem for now. This is an xi so no dynamic suspension of any kind.

 

first thing i'd check is the tire pressures.

 

Are the front and rear tires the same brand and model with just mileage difference?
Did you compensate for the full load by increasing the psi? I have had my 2008 535i with four adults and a full trunk and have expereinced none of your problems; but, I significantly increased the psi for the trip.
I have experienced your problems when one or more tires has a lot less air than the others. I can't comment on the other changes you have made.

 

Xi's have no sports suspension. So with load it will sway. Upgrade the shocks or buy coils to fix. I have an Xi with sports package and whenever I drive spirited I have to really counteract the bodyroll with just myself in the car.

 

Xi's have no sports suspension. So with load it will sway. Upgrade the shocks or buy coils to fix. I have an Xi with sports package and whenever I drive spirited I have to really counteract the bodyroll with just myself in the car.

 

what was the cross winds like. You do know that our cars handle like yatchs in the wind.

 

yep - same tires. The rear ones measured almost new tread depth so I was able to keep them with my new set even with AWD.

Good thought on the tire pressure - i'll check that out and raise it a bit before I hit the road again.

 

KW V3s was on my list until I "had" to get the new wheels earlier than anticipated. I think your right - being able to adjust the suspension should make a big difference in these situations too.

These kinds of road trips and luggage for me has always been in the mini van so maybe the affect on the handling is just a little more un-expected to me in a car.

 

Wind was OK, but I know what you mean. Passing semis and buses really pushed me over a few times coming past their front bumper

 

went on a 1300 mile round trip and after a few times getting nudged over by the big rigs wind id just steer slightly against it....but I can tell you the car should never feel unsettled under normal conditions, maybe its the combination of to many changes , ex. different tires/sway bar in the back only/lots of weight in the car, full load max will do it. How did the car feel on the way back?? or since??