Advice wanted on new wheels

Hey Guys,

My current Kumho tires are shot. 30k miles for tires that were like 85$ each finally wearing down. They are on the factory rims and I was thinking about just upgrading wheels and tires. I am on tirerack looking at some Adventi Racing B2 Denaro's which are 17x7. They seem to be on the lighter side for 17's. Now I have a few questions:

1. Is there a noticable gas milage drop going from 16x6 stock to 17x7? I'd like the think that the extra inch of contact would add rolling resistance but from what i found searching the answer seems to be no.
2. With being lowered on tokico blues and eibach's will I rub with 215's?
3. Is there much differece, really, between 215/40/17 and 205/45/17? I have read though what the numbers mean and I still don't get how much different they are.
4. Anyone have experience with the ContiExtreme Contact DSW's? I'm between them and the ContiProContact. Its a 70$ difference between them and I don't want to sound like i'm cheaping out but whats the big difference? Speed rating isn't a huge deal for me since I don't think i've had the car over 80-85 since I've owned it.

Never having bought new rims before I'm wanting ask before I buy.

thanks!

1. There shouldn't be a big difference in gas mileage between the two, maybe .5 mpg at most. The weight of the wheels being more important in that matter.
2. If you get wheels with the same offset as the factory msp wheels you will not rub with 215/40-17 tires if the offset it +40 or lower you may have to roll the rear quarters a bit, front will be fine though
3. 215 40 17 will be wider by approx 10mm vs 2054517 which will have a slightly taller sidewall. I would recommend 2154017 or even 2154517 which is the factory MSP size and it fills the wheel wells nice when lowered
4. Conti DWS are nice tires for performance and snow traction. speed ratings also affect the handling characteristics of the car. A higher speed rating has a stiffer sidewall allowing the car to handle better, but you will also get a harsher ride. I believe the minimum speed rating for the P5 is a v-rating. Most tire shops won't put a lower rating than what the factory calls for on the car.