Do tires and/or suspension components "break-in"? After 800 miles my AT RX-8 with the sport package feels a lot softer than when new. It's possible I'm adapting to the initially harsh ride, but it does feel a lot softer now.

I believe shock absorbers do break-in - they seem to have an initial adjustment period where some harshness disappears, but that period is unrelated to normal softening through routine wear over the course of years (ie they don't continue to soften at the same rate).

Tires definitely do break in, but not in terms of ride comfort. All tires have a mould release compound on the surface when they're new - out of the mould, they are slippery and have significantly less grip in the first couple of hundred miles. Many are the broken cars where the owner has left the tire shop with his new tires, and wanted to try them out on the first set of corners, only to find out they have far less grip than the old tires just removed! After a couple of hundred miles, the mould release compound has worn off, and the tires will have their full level of grip and responsiveness. Ride quality won't change - unless, of course, the dealer or tire installer set the initial pressures incorrectly! Then, when adjusted, the ride can often be significantly smoother, but that's not a function of breakin, just poor service. ;)

Regards,
Gordon

Check the air pressure. If it is colder now than when you got the car, cold tire pressure goes down and the ride could seem softer. Set to 32lbs COLD (less than 1 mile driven) all around. :)

Yes, everything has some break in point. You wear off the mold release of the tire, and put it through some heat cycles, but that normally affects handling, not ride. Shocks and springs have a little break-in period, and like the rubber tires, all of your suspension bushings (whether rubber, poly, or any other flexible material) have a definite work in period. Even sway bars have a little break-in period (they will have a little affect on ride quality).

This is why you should drive your car for a short period after changing suspension components, before you get an alignment. That way, the new components have broken in and settled, and you get a more accurate alignment that will stay that way longer.

I would say, though, that a significant portion of the "different feel" of the car is you getting used to it.

---jps