Mobil One 5W-30 or a similar
synthetic oil will work well in low temp conditions.
I cannot understand why all these
street driven Cobras have
oil coolers, especially in cooler regions. I know you gotta have them for looks, but they don't allow the
oil to get to proper operating temps. My oil temp runs about 180 in cool weather without the cooler hooked up, and I haven't ever seen it go above 200 in hot weather.