Same gas mileage with 4x4 and 2wd | Ford Explorer Forums - Serious Explorations

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Same gas mileage with 4x4 and 2wd


February 19, 2009
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Year, Model & Trim Level
'96 Explorer Eddie Bauer
I believe I have a faulty speed sensor on the transfer case which causes the 4x4 and 4x4 Low lights to flash if I drive over 35mph. The 4x4 still works, but with the flashing lights. In 4x4 Auto, I think the fronts are engaging all the time.

While I am waiting on the part to arrive, I would like to know if a faulty speed sensor would cause the 4x4 to engage all time? The reason why I ask is because I see no difference in fuel economy with or without the 4x4 engaged (14-15 mpg Highway). However, in 2wd and driving in the snow, I can spin the rears fine so I'm wondering if the sensors are throwing the control unit off.

BTW, I have done a tune-up (plugs, wires, fuel filter, pcv valve, air filter, changed engine, transmission, and tc oil)