tial is activated, the driver sees agreen light flash on the instrument panel. Automatic lock-up can be initiated with wheel slip differences as low as haif a mile per hour, but the threshold values at which lock-up occurs are variable. At higher speeds, the system permits larger differences than at low ones. Since other influences such as different tire diameters or variations in air pressure can lead to differences in wheel revolution without slip being present, “teachable” modules are used which recognize such factors and take them into account.

Finally, there is a switch on the console by which the driver can activate the longitudinal and transverse differential locks. This full traction program is really intended for stump pulling and stuck-in-the-mud starts and can be released manually. If the driver forgets, the control unit automatically switches the traction program off at speeds of over 25 mph or whenever ABS is required.

A track correcting rear axle and no torsion bars

To accommodate the four-wheel-drive system and ABS brakes, new front and rear axles were designed. The rear axle deletes torsion bars in favor of coilover spring and shock units with inner semi-trailing arms whichhaveatrack correcting effect when strong lateral forces are present. The basic function is similar to the Weissach axle of the 928. The new MacPherson front axle has altered geometry which provides the negative scrub radius required by the ABS system. As with the

Extendible rear spoiler, which raises automatically at 50 mph, reduces lift and improves engine cooling via altered pressure cOnditions around the taiL

JANUARY, 1989