Does Route Elevation Profile Make a Huge Difference?

I would bet the around-the-hill route is better. It is slightly shorter and it looks like it will be done at a lower average speed which favors extending EV range.

 

For fuel efficiency, 11% should be OK as an uphill, but not as a downhill. Not only is downhill regeneration less efficient than coasting or gliding, but the battery will fill up about half way down the 1000 foot descent. The remainder of the descent energy must be thrown away as engine compression drag and brake friction.(error, see below)

Depending on speed, 2% or 3% downhill grades allow full recovery of the energy needed to climb. As the descent steepens for any great distance, some efficiency loss become inevitable.

Only you can judge the tradeoff between fuel efficiency and time efficiency.

I figure my Garmin Ecoroute is essentially useless. It only knows one MPG figure for city type roads and one MPG figure for highways, and nothing else. No speed or elevation relationships are factored in.

 

try inputting yer info. at jurassictest.ch/GR/ use the LEAF and insert 2.7 KWH for the battery size

 

i have to disagree with fuzzy. while that maybe true for prius, i don't see how downhill could be less efficient for pip. there will be plenty of battery space to regen after the uphill. perhaps he didn't notice the pip forum. that being said, slower and shorter will be way more efficient than a long grade. you'll never make up downhill what you lost uphill. try both and report back to us. 6 minutes? you must be really busy!

 

Sorry about not noticing that this new thread was in the PIP forum. You are right, the PIP's battery will not fill up on a mere 1000 foot descent.

Next question, does the PIP have enough regen power to hold to speed limit on an 11% downgrade? I don't believe my non-PIP does, so at that steepness some energy must be burned off as engine compression or brake friction regardless of how much room is left in the battery.

 

good question. how would you know, if the regen bar isn't filled all the way? i know on the shortish very steep hills we have around here, it doesn't fill. but maybe you would pick up momentum on a long grade.

 

How long is the uphill portion? Since it appears that you are going to use all of the EV charge, you might want to try switching to HV about a mile before you get to the hill. This will get the ICE up to operating temp and allow it to take you up the hill. Use the EV for the remainder of the route. Going uphill uses a lot of EV juice.

 

yikes, that's an extra year over a working lifetime! do you work for the government?

 

tried twice to put the jurassictest.ch/GR/ link in but priuschat won't let me, tried both chrome and explorer

 

jurassictest.ch/GR/


strip off the "http://" part before posting.

 

nope, doesn't work because I just manually put in "www" jurassictest.ch/GR/

 

It only happens with that link, all the other links I have posted work

 

tried it with the http:// attached

 

as you can see that doesn't work either

 

Learn how to glide on the downhill section and you'll make up for the mpg lost going uphill enough that you won't have to worry about it and you keep your 6minutes. My commute consists of a 1,200ft. Elevation change and in the summer I was getting 54-58mpg uphill and 75-90mpg going downhill. The average of the trip to and from work was then 64.5mpg to 74mpg in ideal weather and speeds. I can do better if there were no elevation change but not enough that I care. Learn how to go slower uphill and glide on the downhill sections!

I don't drive a PIP but the idea is the same.