I'm confused by some aspects of wheel offset :duh:
I understand the concept, and I assume that it's a positive offset that the IS200 has. I understand that offset is important in terms of whether the wheel is going to foul on the inside of the car (e.g. suspension components) or stick out too far (past the arches).
However, what I don't understand specifically is what a valid offset range would be for different wheel widths. I've looked at Mat's posting as quoted below :
As an example, with 7.5 inch wheels, the correct offset for the front seems to say "42 and up". To me, that means an offset of 42 or greater (numerically, e.g. 43, 44, 45, 50, etc). However, using the offset calculator here, if I start with a 7" wheels with 50 offset (I think that's right for the IS200 OEM alloys ?), and put in that I'm going to a 7.5" wheel with 42 offset, then it tells me I've got 2mm more inner clearance and the wheels stick out an extra 14mm, so I presume that's ok.
However, what's confusing me is when I start playing with the numbers. Given that the table above says "42 and up", as I start increasing the offset, e.g. 43, 44 etc, I start reducing inner clearance (and making them stick out less). If I get to 45 offset then I've got 1mm less inner clearance, and going further at ET48 I've got 4mm less inner clearance.
So am I understanding the wording "and up" correctly in the above table ? Surely it can't mean that anything that is 42 and higher will fit fine, because if you go up more than a few mm you're reducing inner clearance and at some point will presumably hit the inside of the car.
Similarly at ET41, the calculator shows that I've got even more inner clearance, but the wheels start sticking out even more.
So is the table above in fact showing the minimum offsets required to stop your wheels poking out past the arches, and saying nothing about coming into contact with the inner parts of the car ?
I get the feeling that I'm totally missing something here !