BenzWorld Senior Member
Date registered: Mar 2006
Vehicle: 2000 E55 AMG
Location: San Rafael, CA
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
* The appearance of width is created only with a wider rim, not a wider tire.
* The optimum rim width for a 245 section width is 8.0".
* The correct plus size (17 to 18) is 245/35/18.
* The root of your problem stems from an oversized section height which is significantly enhanced with an oversized section width. In essence, your rear tire is too tall and too fat to produce a optimum contact patch on any given road. Hence, a bad case of the "wobbles."
* In addition, your current rear setup (18 X 7.5: 245/40/18) has "ripped" the envelope in terms of maintaining a safe stock diameter. Note: First, and foremost, in aftermarket plus sizing is producing a wheel diameter within +/- 3% of stock wheel diameter. You are currently at + 3.89% at the rear, and probably at over 4.0% adding a 7.5" rim into the equation. The "wobbles" are only the tip of the iceberg. Other issues may include ABS malfunction, an out of tune suspension geometry, and premature tire wear.
* You have two solutions:
1) 18 X 7.5: 225/40/18 on all four corners.
2) Mount an 18 X 8: 245/35/18 at the rear, and turn the illusion of width into reality.
On a final note: Personally, I would opt for the refund, and locate a reputable, and informed, wheel/tire shop.
Last edited by ruBENZ_00E55; 05-20-2006 at 10:30 PM.