Transmission
The Z06 utilizes the specially built M12 6-speed manual transmission. While outwardly similar to the base-model MM6 manual transmission, the M12 transmission is unique to the Z06, and not available on other Corvettes, i.e., coupés and convertibles. The M12 has more aggressive gearing to increase torque multiplication in most forward gears, allowing for more rapid acceleration and more usable torque at higher speeds. A transmission temperature sensor was added to protect the M12 from higher thermal stresses. The sensor warns the driver, via the Driver Information Center, with a "TRANS OVER TEMP" message if transmission temperatures approach their operating limits, and which could lead to damage if the transmission were not allowed to cool down. As with all C5 Corvettes, the transmission is located toward the rear of the vehicle, as a rear-mounted transaxle assembly. This allows a better overall weight distribution for the vehicle, as the weight of the transmission offsets some of the weight of the forward-sitting engine.
The M12 6-speed causes the Z06 model of C5 Corvette to have a lower top speed than a normal C5 despite having a higher RPM limit and more power, this is due to its gearing.
Gear ratio comparisons of MM6 (base-model C5) vs. M12 (Z06):
| Gear | LS1/MM6 | LS6/M12 |
|---|---|---|
| 1st Gear | 2.66:1 | 2.97:1 |
| 2nd Gear | 1.78:1 | 2.07:1 |
| 3rd Gear | 1.30:1 | 1.43:1 |
| 4th Gear | 1.00:1 | 1.00:1 |
| 5th Gear | 0.74:1 | 0.84:1 |
| 6th Gear | 0.50:1 | 0.56:1 |
| Reverse | 2.90:1 | 3.28:1 |
| Axle Ratio | varies | 3.42:1 |
| Final Drive Ratio | varies | 1.91:1 |
Read more about this topic: Chevrolet Corvette C5 Z06