down grade 19 inch wheels to 18 or 17
 

just bought a 2004 Boxster with 19 inch wheels , I have been told that i should take off the 19 and put on 18 or 17.That the car will perform better and get better gas mileage. Being a newbie to the Porsche Boxster i really don't know. also need help
on how to program a new key fob.

Thanks

You certainly don't need any help with your airbags!

That must be Porsche's Dynamic Head Restraint System ?

The dealers can help you with the key fob. I've heard anywhere from $300-500.

There are some tradeoffs with smaller wheels, mostly narrower. Narrower wheels = more efficiency and less drag/ friction, weight, but loss of handling. Wider Wheels = Less efficiency, but better handling and braking with larger surface patch. I am actually thinking myself of getting 17x7.5 all around.

I don't have personal experience of 19" but have run both 17 and 18" on my S. From what I have heard, 17 and 18 handle a little better than 19" but I must say that I think 19 are best looking. For me it depends if you are going to track it or not and I guess the ideal is to have 19 daily and 17 or 18 with slicks for track days......

What happen with the "airbags" photo ? Anyway, there are two schools of thought with regard to wheels. There's the group that's mainly concerned with aesthetics, and the other which is more focussed on performance. However, depending on the application, both objectives can be achieved. With that said, ideally you should be looking for a wheel that will result in a significant reduction in unsprung weight and rotational mass, that also appeals to your eye.

I am with Bfan. I have 19 inch for everyday use, and 18 in for track days. I like the look of the 19's but they are heavier, less selection available and more expensive to replace for the track