Living in Shorewood and working in Bayview, I get a good geogrpahical comparison on the varying cost of gasoline.
There are exceptions of course, but the majority of the time, the cost of regular gas at stations in and around Shorewood and Whitefish Bay is about 10 cents per gallon higher, than in the Bayview area and much of the south side.
I don't get to the out-burbs such as Waukesha, Mequon, etc. It would be interesting to hear from other folks on what they have observed in the disparity of gas prices.
What parts of Milwaukee and the burbs have you noticed that have either much higher or lower costs than the North Shore?