In my travels in my 83 diesel I cruise happily at 65 mph which I use
as an upper limit for my motor. In New Jersey on I-80 I have occasionally
been pushed up to 70 by traffic but i fight this as i dont like to turn
my engine over this fast.

I usually cruise around 60 mph, if i drop below this I have trouble on the
hills (okay in upstate NY they are more like bumps) keeping
up to speed. 

How fast ultimo?  My bunker-burner has pushed me up to 75 mph on the flat
with some pedal left - maybe a little tailwind too ??

sps