My '89 Mazda 626:

The recommended tires were 185/70-14. I replaced them with the same size.
Acceleration was OK at best, and poor going up hills. Also, the amount of
sidewall flex made for poor cornering.

I replaced the original tires with the cheapest ones I could find, a $29
"loss leader" from a regional tire place. One went flat last week, and I
found a crack in the tread at the sidewall. NG...

So, I had some 185/60-14s hanging around and had them mounted. WOW!!! The
acceleration is amazing, even going uphill in 4th gear (I had to downshift
to 3rd before...). Handling is 100% better, and the odometer is finally
right (it was 5% off (-) before...)

Any comments? I haven't been able to 'calibrate' the speedo yet. Even
though the odometer was off before, the speedo was correct according to
three different radar 'speed reminders' they put by the side of the road,
and a couple of 'official' radar readings as well...