what is the perfect offset and width and tire sizes can i get? what bout center bore (hubcentric)? i want a wide aggressive look but still want it to be a smooth riding luxury sl...want to keep the ride as close to stock as i can

 

I have 245/35/20's with 20x8.5 wheels. Also the Eibach kit and it still rides pretty smooth. Not sure about the center bore though...

 

255/35/20 with no rubbing. 20x9 is a perfect fit but you can stretch the rear to a 20 x10 if wanted

 

How much are a decent set of 20s going to raise your weight by? It seems like it would slow the car down quite noticeably.

 

Just went to the track the other day with the 20"s on and I will tell you that with my newer mods, my max is a bit slower, about 2/10 of second slower but I'm trapping 1.5 mph quicker then before. Reason being I lose it in the first 1/8 of a mile, espically in the 60' times not because the wheels are to big, its a minor factor since they are lighter then stock. I couldn't keep them planted and kept spinning through second.