You will definitely feel the difference. You
will likely sense your suspension working on
the highway, more than it used to, dealing
with the extra rotating mass of those wheels.

An 18" rim puts that 23 pounds closer to the
outside than your current wheels. This has a
perceptible effect on not just acceleration,
but also braking (your brakes are trying to
slow rotating weight that is further from the
hub). So... it will impact your performance.

Why the Parada by the way? I have heard the
Tire Rack folks describe that tire as merely
"cosmetic performance". There are way better
tires out there for that money.

T.