I have an 06 BMW 530i with sport package, I did not notice that i run the flat tires, so all the rubber inside the tires are gone. So, I had to replace the tire just one side on the rear left side and it costs me $380 a piece . Instead of getting just one tire for $380 (stock tires), I chose other brand. I bought 2 tires for the rear for $390 brand BF good rich same size with the stock (245/40/18). I notice that the tires are a little bit thicker than the stock one and I felt more body roll on the car when changing lane on High way. I am running about 70 MPH.. So, does everyone ever experince this? Is it because the rear tires are thicker in height? Do I need alignment??

Stock front tires: Bridgestone Potenza RE 050A ( 245/40/18 )

Rear tires : BF Goodrich G-force T/A KDW (245/40/18)

 

For a start what are your sizes of the front and back?

I have BF good rich too. 19/245/35 and they are very good in wet and dry and less noise too.
before I installed the sway bars, there was less body roll on the BF good rich than the stock tyres. maybe it is low pro tyre now.
After installing the sway there is almost no body roll now.
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[quote name='dre23' date='Oct 19 2006, 12:04 AM' post='346519'] I have an 06 BMW 530i with sport package, I did not notice that i run the flat tires, so all the rubber inside the tires are gone. So, I had to replace the tire just one side on the rear left side and it costs me $380 a piece . Instead of getting just one tire for $380 (stock tires), I chose other brand. I bought 2 tires for the rear for $390 brand BF good rich. I notice that the tires are a little bit thicker than the stock one.And I felt more body roll on the car when changing lane on High way. I am running about 70 MPH.. So, does everyone ever experince this? Is it because the rear tires are thicker? [/quote]





yes. you change the height of the car by putting higher sized tires at rear..

(and you might have a little hesitation while the car changes the gears at high rpms)
( it effects the gear ratio when the car is in a improperly lifted from his regular angle)

 

Not sure what you mean by "thicker" thicker in what way? Side wall height? as quad_m said... or ? If thats the case height of the car has changed... but also you introduced more side wall and especially since they are not run flats the side walls flex more... so you'll feel more "rolling" Plus you're just not use to it... new tires... new feeling.

Oh and not to make you feel bad... but how many miles did you have on your tires? Under 20K? are they OEM Dunlop tires? If you answered yes to all those BMW would have replaced your tires for free.

 

Sory, forgot to mention, the size of tires are the same with the stock tires which is 245/40/18.. But, BF Goodrich are thicker in Height...

No, it is not that I am not use to it, but the handling changed a little bit. The car used to fill like sitting in the rail but, now there is a slight change which I mention about the body roll. The tires are OEM BRIDGESTONE POTENZA RE 050A.. I have 13k on them. Are you sure BMW would replace the tires for free?

 

The fronts are: 245/40/18 with Bridgestone Potenza RE 050A
The rears are: 245/40/18 with BF Goodrich G-force T/A KDW

I dont change any height on the car, it s just that the rear tires are a bit taller then the front eventhough the size is the same..

 

that why you need to change all 4 tires no just 2 for best performance.
or at lest all 4 are the same

by the why are your trend same as my 1s?