If you want to use Auto mode all year round, that’s fine, entirely up to you. It won’t hurt the vehicle or the four-wheel drive system. It will increase fuel consumption, but how much of an increase depends on how much the system is called into action. Using Auto mode in perfect weather conditions, on clear dry roads, will increase fuel consumption by about 1 to 2 mpg.
The original system with the 4406 unit reviewed input from feedback sensors (steering, throttle, brake, and propeller-shaft speed) every 20 milliseconds. It would engage the center multi-disc differential when it detected as little as a half an rpm difference between the front and rear wheels. It could detect wheel slip, decide how much torque needed to be allocated, and then transfer it – all in 200 milliseconds. That’s faster than the human eye can blink, which is 300 milliseconds.
The system could control runaway drive wheel spin in as little as a third of a wheel revolution.
The front wheels are always engaged in Auto mode whether they receive torque or not. There is no shifting into or out of four-wheel drive.The only component that moves or is active is the center multi-disc differential, which is inside the transfer case.
The newer systems with the 4416 and 4417 units cut the original response time in half. They sport an uprated dedicated microprocessor for faster processing of sensor feedback.
Expeditions with AdvanceTrac use the four ABS wheel speed sensors, rather than the two sensors on the front and rear propeller-shafts.
The original system with the 4406 unit reviewed input from feedback sensors (steering, throttle, brake, and propeller-shaft speed) every 20 milliseconds. It would engage the center multi-disc differential when it detected as little as a half an rpm difference between the front and rear wheels. It could detect wheel slip, decide how much torque needed to be allocated, and then transfer it – all in 200 milliseconds. That’s faster than the human eye can blink, which is 300 milliseconds.
The system could control runaway drive wheel spin in as little as a third of a wheel revolution.
The front wheels are always engaged in Auto mode whether they receive torque or not. There is no shifting into or out of four-wheel drive.The only component that moves or is active is the center multi-disc differential, which is inside the transfer case.
The newer systems with the 4416 and 4417 units cut the original response time in half. They sport an uprated dedicated microprocessor for faster processing of sensor feedback.
Expeditions with AdvanceTrac use the four ABS wheel speed sensors, rather than the two sensors on the front and rear propeller-shafts.
