Florida to Upstate NY (Saratoga Springs)

jplante4 wrote:

Dutch_12078 wrote:
Surprisingly, the difference in elevation between the I-95/I-26 split in SC and our upstate NY cottage is exactly the same no matter which route we take! The ups and downs must even out either way somewhere along the way to end up at the same elevation... ;)

Well of course. If you start at sea level and end up at sea level, you didn't climb at all :)

What I meant was the amount of time you spend going uphill at 35 mph is greater than the amount of time you spend coasting downhill at 55-65 mph. This is a classic problem I give to my flying students to get them to think about how a headwind effects a flight.

But you missed the return flight part of the discussion, the downwind leg of the flight.

Let’s say I fly 250 miles into a 25 mph headwind, my usual ground speed is 160 mph at which I burn 10.9 gph. My effective speed is now only 135 mph and instead of taking 1.5 hours it takes 1.85 hours and so I burn 20.165 gallons instead of just 16.35 gallons, an extra 3.185 gallons and it takes an extra 20 minutes.

On the return trip though I’m going 185 mph speed over ground because I have a tailwind. So now it only takes 1.35 hours instead of 1.5, so I only burn 14.73 gallons instead of 16.35 gallons, a savings of 1.62 gallons and 9 minutes.

So in the end I really only burned an extra 2.195 gallons on the whole trip. Just like the fuel savings gained by the increased fuel economy going downhill.

Nobody said was a ‘wash’ but it must be taken into account.