1. Pre precursor
refers to the front-engine front precursors, front-wheel drive driving mode.
This drive system is slowly being promoted last century, the 1970s. In modern medium and small passenger cars, multi-use pre-precursor.
Advantages: simple mechanism, rear-drive ratio of saving transmitting power from the shaft to the front motor drives the rear wheels. Save fuel.
disadvantages: the front wheel and to assume two driving and steering functions, and therefore less stable at high speeds. Further, since the drive wheels in the front end of the vehicle body lighter weight, easy uphill drive wheel slip, easy to roll downhill.