I have a good idea of how fast my Mazda RX-8 should be accelerating and recently I have noticed my car has been going...

The traction control signal in my car remains lit and I have not done anything to it. Sometimes the light turns off by...

Your Mazda RX-8 may have slower acceleration due to a clogged air filter. If the air filter is clogged the engine will not be able to suck in enough air to combust the necessary amount of fuel that the engine requires. You can fix this by replacing the air filter with a new one. To replace the air filter, look at: Air Filter Replacement

Sometimes this occurs if you have disconnected the car's battery recently, in this case try waiting it out for a little bit. This issue can also happen if there is a wire loose or a small malfunction in the Mazda RX-8's computer, take this to a specialist to get it checked out. If you have recently installed aftermarket wheels with a different size front to rear, try rotating you tires (look at Wheel Replacement Guide). You can find more answers on the troubleshooting guide: 2004-2008 Mazda RX-8 Troubleshooting