It's amazing what the right size tire can do...
When i bought the neon from my brother, he had slightly bigger tires on it(not sure why) - 195/55-15's, vs. the OE 185/60-15, and even on the drive home, i noticed the speedo was off vs what the scan gauge was reading from the obdII (55 on speedo was really 53, bigger gap as you went faster, but never more than 5 mph) GPS tended to agree with the computer. I just dealt with it.

So finally it was time to change the Tires. The Yokos(yk520's) served me well since i bought the car, but after 4 years, and 40k miles, they were cracked something fierce( sidewalls a sea of cracks, and big nasty looking circumferential between the treads on one of the fronts, one had leaked as low as 21psi ), enough i didn't feel they would make it though the winter.

did my research, settled on a set of Pirelli P4 Four Seasons, in the OE 185/60-15. just went on this morning, and i couldn't believe it on my drive home. the Computer, GPS, and Speedo all agreed that i was doing 55mph!

I'll say it again, it's amazing what Putting on the right size tire can do.

 

going from 55 to 60's & all seasons, how much extra side wall flex do you notice at hwy speeds?

 

1)dunno. i have all of 10 mi on the new tires so far.
2)and not to sound stupid(Too Late!), but how would i notice that @ speed?
3) gotta have all seasons. we get just enough winter that you need something with decent snow traction, but not enough to really warrant a dedicated set of "snow tires" for a small FWD car. (maybe 1 big snow per year lately)

 

55 to 60 series....my guess is that it is not going to be any noticeable amount of less/more flex.