I'm no expert...
* I believe the superlight had 205/45 r17 tires. So if you are on 16
inch rims you have lowered the car. Have you changed any suspension
settings to compensate? * Going +1, +2 etc effectively gives you a bigger wheel with a shorther
sidewall for the same diameter. Sidewalls are a part of the suspension.
ANY car going to a bigger wheel will have a harder ride.
* I wonder if 205 isn't strictly an esthetic choice. Offhand I can't
recall the tire widths on the original NA and NB. But I do believe that
the 12 cylinder Ferraris in the 60's came with 205 width tires. On a
Miata I would say you are gaining a macho look, improved cornering, and
better dry traction but at the cost of ride comfort, higher rolling
resistance, lower fuel economy, etc.
But as I said, I'm no expert...