2018 Ford Expedition ‘sand mode secrets’

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JEDDAH –

For Middle East owners with an eye on the great outdoors, the all-new Expedition’s four-wheel-drive and Terrain Management System opens the region’s remote reaches to adventure for the entire family.

Ford Expedition has always put families first, with class-leading levels of comfort, safety and convenience and now – with its superior off-road ability plus a dedicated driving mode for sand – owners can turn any family trip into a real expedition.

Expedition’s all-new easy-to-use Terrain Management System™ lets customers select from seven special drive modes that help Expedition automatically adapt to different road conditions. This includes Normal for around town driving, Sport for more spirited trips, Tow/Haul for improved towing and hauling performance, Eco for enhanced fuel economy, Grass/Gravel/Snow for loose terrain, Mud/Rut for uneven surfaces, and Sand mode for driving in soft, deep sandy conditions found throughout the Middle East.

“The off-road modes are designed to help drivers navigate conditions they may not be familiar with – like sand,” said Todd Hoevener, Expedition chief programme engineer. “Getting stuck is probably the worst thing that can happen to you as a driver when you’re in the desert with your family and friends in the car. Sand mode just makes it enjoyable to drive with vehicle electronics as a safety net there to help.”

To give the Expedition true go-anywhere capability, Ford fitted four-wheel-drive equipped vehicles with a two-speed transfer case and electronic limited slip differential.

“The electronic limited slip diff enables it to react more quickly when you’re seeing slip on one side versus the other which helps when there is rain or ice, but a locking diff out here in the sand is very important to get that low-speed traction to pull you out of the hole,” Hoevener added.

Expedition’s Terrain Management System (TMS) is an intelligent four-wheel-drive control programme that configures the vehicle for the conditions ahead. It uses a combination of sensors and an onboard gyroscope to work out what the vehicle is doing, and what can be done to assist the driver.

“When you switch between the different modes, what you are looking at is traction, how the engine and transmission adapts, and how the chassis dynamics come together,” Ziyad Dallalah, Ford Middle East’s chief resident engineer, explained.

That usually centres on keeping the vehicle pointing in the right direction by monitoring traction at all four wheels and applying torque, the brakes, traction control – or a mix of each – where needed.

Driving in the desert is a little different. Undulating dunes of soft sand can confuse systems that are designed to work on reasonably level, hard-packed surfaces – while drivers usually need to switch off traction control systems to stop from bogging down in the sand.

“In Sand mode, it’s about staying in lower gears and disabling as much traction control as possible. The TMS automatically limits the amount of assistance they offer and also manages both engine speed and transmission shifts – holding lower gears longer so that you can use high rpm and high wheel speed,” Dallalah explained.

The system uses a gyroscope to build a picture of what’s going on with the vehicle; how much it is sliding (yaw) and rolling (roll). Based on calibrations made during in-market testing in the UAE and other centres around the globe, the TMS then sends torque to the appropriate wheels, allowing them to spin even though the vehicle is moving at very low speeds.

“This is what you need for low speed sand driving if you do get in the deep and need to crawl out. The cleverness of the software and electronics, paired with all the mechanical advantages of the low-speed transfer case and the electronic locking rear diff really do make the Expedition a very capable large SUV for off-road adventures,” Dallalah noted. — SG


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