Here in Europe we dont seem to get this problem in any form yet we have lots of roundabouts and often do 270 deg right handers.
Do either there is something different about your Duratecs or maybe you just dont go fast enough on the bends to keep the oil warm
Actually maybe something in that. US cars have such awfully soft suspension, your cars probably are leaning at a greater angle than European ones. Has anyone with an oil pressure guage actually watched whats happens on a severe bend. My Oil Pressure doesn't budge, for left or right handers