Wheels Question

I am thinking about getting some 17" wheels. My car is dropped 3 1/4" So I need to know what offsets would work so that they would tuck nice and not rub. And what are the differences in offsets.

And what are the differences in offsets.

Positive offsets make the wheel go outwards and negative offsets make the wheel go inwards. I think...

So what offset would I need that wont rub. Someone please help.

+45mm

I had about a 4in drop and then I got some 17s
http://images.cardomain.com/member_images/12/web/300000-300999/300292_14_full.jpg
I figured id get a camber kit to help out so i didnt ruin my tires. I put it on and took it to get aligned. what i then found out is a piece of the subframe needs to be notched out so the upper a arm can swing by. i dont have any pics of where it needs notched out but ill try and get some. so i got my camber on and my car was still dropped about 4 in. i didn't scrape but my tires rubbed the wheel wells so i raised it and got realigned. its pretty low as you can see in the pics and it wont scrape most of the time unless i hit a bigger bump goin pretty quick. still when it does rub now it wont bend the fenders or anything the wheels are 17x7 with a 40mm offset

So does +45 stick out on the sides further than a +40

So does +45 stick out on the sides further than a +40
nope. lower offsets stick out more. you need a +40 or higher to tuck with a 17.

offset/backspacing is the distance from the wheels mounting point to the edge of the rim or the distance from the mounting surface to the center line of wheel.

Offset & backspacing are 2 different things often confused, even wheel site call it offset when its backspacing . . .
http://www.imagestation.com/picture/sraid95/p696104f201d905fafe0682f3ba3bd217/fa24692c.jpg

I think even a 40 would rub with 17s and a 3.25" drop.. I've had 38 15" rims and they rubbed, and my +42 C8s are very close to rubbing (but not quite)...

To be safe, stay in the 42-45 range.. 45 being stock and most ideal.

Thanks for the help everyone I understand now.