Up here in Canada, the fuel price differential is less severe than it is stateside. Currently, in Edmonton, Alberta, gasoline costs between 65-71 c/L, whereas the least expensive diesel fuel is 78.4c/L
Until Ultra-low Sulfur Diesel formulations came out, Diesel tended to be cheaper than gasoline here in summer, and more expensive than gasoline when winter comes. The past year or two, as all stations here became ULSD fuel only, the price has tended to be at parity with gasoline per volume, or higher.
Part of the price competition for diesel in winter in North America is the large number of fuel-oil heated homes in the Eastern seaboard -- Both in the US and Canada. The other big issue I see is simply supply and demand: With a majority of gasoline powered vehicles, less diesel is produced on this continent.
And at the macro-economic level, the US and Europe have been cross-shipping overproductions of diesel (US -> Europe), and gasoline (Europe -> US) which has kept diesel prices higher in N. America than the previous year, while the gasoline imports have helped stabilize prices for that fuel more than otherwise. This is all aside of taxes, tarriffs, and subsidies on fuels.
Oh, and one more con for the diesel list, as an owner: Harder cold starting in VERY cold winter temperatures.
I'm regretting that I did not put my scheme for a two-battery relocate to my trunk of my Jetta this winter season. It's only mid-December, and the first -25C temperatures this weekend kept my car from starting.
Time to post this, and go hunt down a way of insulating my battery better to help retain more heat.