Marcus: Thanks for the simple calculations and corresponding fuel tank sizes for the M-class and C-class.
Michael: Thanks for your input as well. It seems that most comments in this thread are of the opinion that I should go with an M-class. For my type of driving, I guess it makes sense, especially dealing with snow and ice.
I'll have to drive both and see, but it looks like I should still consider an ML. Question: Does the w163 ML have 4Matic activated all the time, or can it be turned off? I have the same question regarding all Merc sedans that have 4Matic.
Also Marcus, based on your provided fuel tank sizes and mpg ratings for the M-class and C-class, I surprisingly found out that the ML will actually be cheaper, fuel wise, on a week-to-week basis than the C. Even though the ML costs more per day in fuel than the C, it will give me around 7.22 days worth on a full tank vs. 5.84 days worth on a full tank for the C. The cumulative effect is that the ML will turn out to save me money over the C on fuel costs. Hmm....
Marcus: Are your C-class mpg rating for the C240 or C280?
I know I over-analyze/think things, but I want to make sure I choose the right Benz for me, even though I'm not buying until Dec of this year.
Addendum: Marcus, where did you get the fuel tank size for the w163 ML from? According to the w163 ML page at consumer reports,
the fuel tank size is 19 gal.