New wheels make old suspension worse?

[thefitter]

Here’s car:

2002 325i, 100k miles without sport package.

Here’s the story:

I decided to put some new wheels and tires on my older car after I got my ‘07 335i, partly because I wanted to improve the handling a bit and partly because the OEM wheels 16” x 7” +47mm offset with Goodyear Eagle F1s, had been curbed so many times I wanted to dress up the old girl a little as well.

I purchased a set of 17” x 8” BBS RKs with +35mm offset. Good brand, good wheels, good price and very light at 18 lbs. Basically I went up 1” in width and 1” in diameter and down about 9 lbs each wheel, so nothing drastic at all except the weight. The tires are of course Michelin Pilot Sport II, what else?

I had the wheels and tires sent mounted and balanced from tire rack to a authorized tire rack installer who is a well established exclusively BMW as well as Dinan authorized shop so they know their stuff. When I picked up the car I instantly noticed the difference. Steering was much quicker and sharper. It felt like a different car! I could not believe how much of a difference this wheel and tire combo made. I was very happy. But later I noticed that on the freeway at higher speeds the car seemed very “squirrelly”. Every bump in the road and every twitch of the steering wheel was causing the car to react. It was like I was driving a car with old style power steering at times. I felt like I had to have both hands on the wheel at speeds above 80. At first I thought that maybe the wheels are so quick and the tires so sticky now that this is just normal. I also thought that I was unfairly comparing the old girl to our new thoroughbred with the active steering and sport suspension. My wife commented that she did not like it at all so I decided to have it checked out. I took it back to the shop that did the install of the new wheels and told them my concerns and asked them to check it out. They test drove it and said that they thought that something was defiantly “off” and that it did not seem “planted” and was not handling the way it should. At first they thought maybe the wheels were not right for the car but after checking the size and offset they ruled that out. I also talked to the guys at Tire rack and confirmed that these wheels were right for this car. Then they checked the suspension and although the suspension does have 100k miles on it there is nothing really wrong with it. The best they could come up with was that they thought that the suspension was worn-out (a point that the guys at the Tire rack brought up) and maybe not aggressive enough for the new hot wheel and tire package and that I should upgrade it. They suggested the Dinan stage 1 suspension package at about $2200.00 complete and installed. My concern is that they cannot categorically state that this will solve the problem so I’m not all that sure about dropping that much cash on only a maybe. On top of that I only plan on keeping this car until about September or October of this year.

So that’s the story. I would appreciate any insight and suggestions’ that any of you would care to offer.

[Needle Damage]

If the suspension has never been touched, there are a few parts down there that are probably worn out at 100k miles. (like sway & control arm bushings, strut mounts, etc)

Don't throw parts at a problem until you know what the problem is.