Forty9

When driving from the United States into Canada, our new E400 wagon (with American specifications) immediately recognized that it was in a country in which distances and speed limits were measured in kilometers rather than miles, and (though I did not use the menus to convert the speedometer and odometer from miles to kilometers while we were in Canada but chose to let them continue to register speed and distance in miles) the distronic system instantly adjusted to the speed limits in kilometers and regulated our speed accordingly--which was a boon for driving, since we had to travel more than 2000 miles before crossing the border back into the United States. But, when we returned to the United States last week, the car did not immediately--or ever afterward, so far--recognize that we were back in the United States. It did not change the time zone at the border (I did that manually through the menus), nor did it recognize that we were back in a country where speed limits and distances are measured in miles. In the left-hand display behind the steering wheel, in the lower left where the speed for cruise control is displayed with a little icon of a steering wheel, the speed is still given in kilometers, although the speedometer and odometer remain (as ever) in miles. The problem is that now the car, when I pass an American speed limit sign of 65, thinks the speed limit is 65 kilometers, rather than 65 miles, and slows me down accordingly. So I can't use distronic until the problem is corrected, unless I want to drive at 62% of the speed limit.

There doesn't seem to be any simple way to fix the problem using the menus in the car, and Mercedes advisors reached through the telephone assistance have so far been useless in offering advice on how to fix it. I have an appointment to take the car in to my local Mercedes dealer for service next week to see if they can solve the problem, but, in the meantime, because the service technicians at the dealer admit they have never encountered this problem, and because this forum has people who seem to know all the answers, I wonder if anyone has encountered and solved this problem or can offer any good advice.

While I'm at it, here's another curious problem. The sticker by my gasoline filler port tells me to use no gasoline under 91 octane but, as far as I can determine, no gasoline with octane higher than 90 is available for sale in my state. I had no trouble finding 91 octane gasoline in Canada, however, except once when I had to buy 94 instead. Has anyone else encountered and solved this problem?