Originally Posted by Yorksail00

High mode increases height by 2" in the front and 2.4 inches in the rear from Normal height. It will lower back to N if speeds exceed 18 mpg*.
If the vehicle speed exceeds 25 mph in 4 Low the height will drop to 1 inch above N. As in drops ~1 inch below the High setting. When in 4 Low on uneven surfaces and your speed exceeds 2 mph, it will automatically raise to High mode.

Low mode lowers the front by 2.4 inches in the front and 1.6 inches in the rear. It will return to N when speeds exceed 7 mph*.

interesting side note:
When in 4 Low/Crawl Control, the vehicle may go into Extra High mode, which can raise it 0.8 inches, or higher in some cases. That's over the normal High setting. Speeds greater than 6 mph will lower it back to the regular High setting.

Speeds greater than 50 mph causes the suspension to lower in most cases (the front more than the rear for aerodynamics). Throughout road travel you will feel the suspension modulate. Oftentimes when stopping you will feel the rear come down, followed by the front.