8bender, I run Mobil 1 15W50 in our older vintage MB automobiles (1991 300CE and 1995 E320), which had 15W40 as factory fill, year round. The older engines didn't have the tight tolerances of the newer engines and operate fine with the higher viscosity oil. The Recommended Engine Oil vs. Ambient Temperature Chart in the Owner's Manual for our 1991 300CE shows that 15W50 oil is fine for temperatures down to minus 4 degrees F. NJ and PA rarely see temperatures in the teens.

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Fred Hoelzle