In Reply to: Tire size issues (Eddie are you out there?) posted by MikeW on September 21, 1999 at 09:45:57:
: I read alot about guys changing tire and wheel sizes on their cars. However, don't the cars come with their suspensions tuned for the tire size they come with? I know about the +1, +2 thing (10mm greater tread width, 10 profiles points lower, one inch greater wheel diameter) to preserve rolling radius. But can't even this screw up ride and handling, let alone if you don't follow the formula? Does the suspenstion have to be retuned to match a new tire size, and it this doable with just alignment adjustments?
: I have two reasons for asking this. I'm thinking about a 328Ci. Like the sport package (both seats and wheels) but not wild about the OEM tires (Bridgestone Turenza). Maybe it's worth getting a non sport package and doing my own upgrade with the tires I want (Bridgestone S02PP). But the non sport is set up for 205/60-16 all around, not the 225/45-17 and 240/40-17 that come with the sport package. Will going wider/lower profile screw up the suspension tuning on the non-sport car.
: Also, I'd probably need winter tires (I've slid backwards down too many hills). The Blizzak M01/M02 look good, but I understand that narrower/taller tires are better in snow. Because of this, I'd probably go with a -2 setup, especially if I went for the sport package. Now I know the snows will have less performance vs the summer tires, but will changes sizes screw things up even more? Also, I can't find a Blizzak listed in a -2 size for the 328 sport package. What would I use?
First, the tires would be 205/55/16. The 225/45R17, or 235/40R17s work fine, with a minimal difference in ride height & minimal loss in ride comfort. I went from 15 up +2 to 17" and have been very pleased (S02PPs) with the ride. I went with non sport because AI planned on adding spring & wheels/tires initially. Looking back, I miss the seats, but the wheels being the biggest thing, are really the way to go from a performance standpoint.
As for snows, we typically try to get you into a slightly narrower tire to improve traction if possible. On the 323 we can have you downsize to 15", not really giving you a taller tire, but keeping the overall diameter the same, plus it saves you some cash.
call me to discuss futher! 800.428.8355, ext 369