1. I've always wondered if going wider adds friction...
My physics class would so NO...but I am all ears to those who know the real world and what they know from experience (as opposed to myth and folk law)....
As an engineer, I know that friction does not depend upon surface area. As a car nut, I know that wider tires have better traction. How do you explain this contradiction?

note: 255/40's is as wide as we can go on our SLK32's 17" rims, where as you SRT guys are pushing 285's on 19's...= much more contact area.

2. Another thought as well was a discussion around how much wider on a rim can you go..
My thoughts are - if your tire is much wider than your rim, the tire wall will bulge and not provide the cornering stability you may want from time to time. The SLK32 has 217mm rims (8.5") - so with 245/45/17 tires as spec you get [14mm overhang] on each side.
With my 255/40's I've increased that to 19mm and you can definitely tell (visually).

3. But....does this added bulge help you with hookup?
Much like the top fuelers - as you hook - you have some absorption in the tire wall which stores energy and helps you even out hookup. Is this a real consideration?
Low profile tires would obviously work in the opposite direction = harder to hook. Is this your experience?
Would I get better hookup if I went to a 16" rim with a 245/45? There are factory SLK32's that came out with such a tire configuration.