Kimosabe wrote:So is it better in terms of fuel economy to :
a) spend longer at the desired target speed ?
or
b) spend less time at the desired target speed ?
I was told answer 'a' is correct (and that sounds about right to me)
If I had to guess (and I'm not equipped to do anything more than guess), I'd have thought that whatever difference there might be in fuel used for a briefer, more rapid acceleration from say 30 to 60 compared to a longer, gentler acceleration from 30 to 60 would be negligible compared to the increase in fuel consumption in the former case due to spending longer at 60. I'm assuming that what you do in both cases once reaching 60 is hold that desired target speed until the same point on the road.
Kimosabe wrote:The fuel cut off answer seems about right.
The fuel cut off answer won't be applicable if you intend to spend any time at the desired speed - you won't maintain speed if you've lifted off.
If, on the other hand, you're comparing the two different acceleration profiles followed in both cases by immediately lifting off, I might guess a different answer (although I'm not sure what it would be).