it's not terrible or anything, the circumference will be a little different but you'll get that no matter what when you use a spare

personal pref.

by having two different size tires on a moving car. Had not thought about NOT having a spare (though I like the idea of less weight).

I think I will keep the spare...one never knows when it will come in handy.

and an 18 inch wheel with 45's or even 50's. The smaller the sidewall, the smaller the rolling diameter of a bigger wheel.

And for what its worth, I drove on my full size spare with three RS6's for about a hundred miles. Smooth as butter.

its all in the books...shortest distance to the next tire shop and not driving faster than 50MPH to avoid any damage.
The spare tire will be the weakest link in that case ,it is a lightweight full size, but thinner and narrower (205 I think).
There are actually instructions written on the tire and in the manual, if you follow those then you should be fine.

And keep in mind - inflation after installation - see manual.

without removing tire in an emergency.<ul><li><a href="http://www.safetyseal.com/store/autokits.htm">http://www.safetyseal.com/store/autokits.htm</a</li></ul>