Wondering if some of you hypermilers out there could give me some advice. I've tried to read as much as I can about PNG, but one thing I'm unclear on. Some articles say to accellerate gently up to speed before gliding. One such article is:

http://hybridcars.about.com/od/owner...seandglide.htm

With the following quote:
"First, Pulse - Getting The Car Up To Speed
When the car needs to get up to speed, gently accelerate. As much as possible, avoid using energy from the large hybrid battery while accelerating."

A competing statement can be found on page 15 of the following pdf file:

http://www.rmi.org/images/other/Newsletter/NLRMIsummer05.pdf

This one says that a Prius should be accelerated briskly because it is more efficient at higher speeds.

So, what is the correct method for my HCHII? Watching my instantaneous MPG, it "feels" like the brisk acceleration is better, especially if the speed limit is 45 mph. The car glides very nicely at 45, and I can usually get some pretty good stretches in "EV" mode at that speed.

So, a little help for a wannabe?

 

This is a highly debated topic and I honestly do not know the correct answer. Clearly if you accelerated too slow you would never get out of the lower gears and into your tallest gear so going too slow is clearly bad. OTOH I'm sure gassing it to the point of tire squeeling is also not a good way to get the best mileage. Somewhere in the middle must lie the truth. Personally I prefer medium to brisk just because really gentle acceleration is boring. It might depend on the car as well. Some of the best hypermilers swear by the really gentle acceleration technique.

 

If conditions exist I accelerate at almost the slowest rate possible.

For instance on a flat road from 0-35 I'll "surf" the edge to just barely keep the Assist on. (Without Assist the acceleration rate is zero)
Between 35-40 I'll raise it to about 60MPH and accelerate from there.
Once I get to around 45 I can raise it higher between 70-80MPG.

0-45MPH in about 40 seconds.
But that's only if I'm solo. If I have passengers I'll gas it a little more.

 

Thanks for the info. I just now found the thread (and spent the better part of an hour or so reading), "Pulse and Glide shouldn't work vs. Cruise control" and I see what you mean about a much debated topic!

 

"Much debated" topics are often that way because there is relative merit on both sides. And the argument is not so clear as to have a hands-down winner.

For this debate, I have found the difference to be small enough to recommend that you make your own decision, within reason of course. Don't over-accelerate, but beyond that, you choose whether you would like to ever-so-slowly accelerate, or whether you would like to get up to speed quicker, thus getting into 'glide' mode sooner.

 

my acceleration feels rather quick to me, but this could be attributed to always accelerating slowly at all other times. during a pulse i accelrate to the point that i dont break the 2150 RPM or so barrier, so anything up to that is fair game. that's just how i do it, and i've seen some pretty good results, especially on the long stretches (when possible).

 

Precisely this is being discussed more specifically, with more specific answers, in the Prius forum:
https://www.greenhybrid.com/discuss/...ad.php?p=99317

To generalize what we've found so far... using the battery is the #1 thing to avoid to achieve very high mileage. The cost of generating this electricity is too expensive - gas engine turning to fill battery to then dump back out to drive the wheels - all those conversions result in very low efficiency.

You do want to push the ICE at low RPM (the linked PDF is right about that), but not to the point that the car kicks in Battery Assist (I doubt the author realized that). On the Prius this appears as a yellow arrow coming from the battery. On the Honda Civic Hybrid this appears as the Assist bar growing - your goal should be to avoid the Assist bar when accellerating.

So far in the Prius this strategy has moved me from a max of ~55mpg with careful driving to at least 60mpg - and my mpg is still going up.