My 300SD can see around 30-31mpg if I granny drive and go only about 50-55mph......also, if when I am driving around the city I shift as soon as possible (so I am essentially always plundering along at 1000-1200rpm in 4th) I have seen as high as 27.8mpg with it being ALL city driving! It takes patience and relaxation, but its possible to get some excellent MPG's out of these cars. Today I filled up with about 20% of my miles being granny driving in the city and the rest was at about 75mph freeway.....I got 24.6, not too bad....diesel was also only $4.35, lowest I've paid in ages!

As for the bit about "what your time is worth vs the cost of fuel/driving faster"

Are you saying that your time is worth more than extra damage to the environment and wasted fuel/energy?

If everyone drove super conservative we would have:

1. Backed up freeways
2. Far lower fuel consumption
3. Cleaner air and less pollution

I'm not saying I always go slow, but I do go within 5mph of the speed limit 97% of the time.....what annoys me are the escalades that go by at 90mph on the freeway....insanity. They are literally shoveling money into the tank.

__________________
-diesel is not just a fuel, its a way of life-
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'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)