Not sure how scientific this was but I ran a series of tests today.
Conditions were:
80 Degree high humidity Possibly 90% on the edge of rain,
Engine completely warmed up for about 1/2 hour of driving,
Battery Pack (SOC) is 4 bars off of full,
No A/C or any other accessories,
Windows up,
etc

I did tests of 2 terrains:
1. slight incline
2. Up/down a series of very large hills over 2 miles.

The 1st test was on a straight strip of road that has a linear slight incline.
I did a series of "Control" tests to measure the road itself and this is what I found:
The road chosen is 1/2 mile long.
The HCH maintains 50MPH with FCD held at 44MPG.(40 + 1 bar) on ascent.
Other way around on the decent it maintans 50MPH at 84MPG.
Hopefully that will show the grade as it is not level.

I did a series of tests to measure fuel consumed going 0-50 on ASCENT ONLY.
Once 50MPH is reached the FCD is adjusted to 42MPG to maintain speed.
MPG is measured at the 1/2 mile mark. Tests were ran 3 times, each had about the same results.
This is what I measured:

Full throttle: 0-50 in 10 seconds 19MPG
FCD held at 20MPG: 0-50 in 31sec 25MPG
Very slow acceleration: 0-42 in 56 sec (Reached 1/2 mile) 30MPG

Big hill tests both ways up & down:
Since these hills aren't typically from zero acceleration, they begin at 50MPH.
FCD is reset at the base of the bottom of the hill or at the top, depending on the test.
These are large hills and I'm guessing 2K feet over the 2 miles.
Perhaps later I can snap and post a picture of these monsters.
MPG after 2 miles:

CRUISE CONTROL ON:
DECENT: 85MPG
ASCENT: 43MPG

CRUISE CONTROL OFF:
DECENT: Driving with the load: 90MPG
ASCENT: Slowing on ascent, easy gradual acceleration on flats: 59MPG

My conclusion from this is to keep off of Cruise Control, always drive with the load and accelerate as gradually as practically possible.

Comments?

 

Hot Georgia,

Great information. what does the acronym FCD stand for? I'm thinking it stands for Fuel Charge Display?

Thanks!

 

FCD is Fuel Consumption Display.
I've taken my test results on my daily commute and broke my old record and at the end drove 41 miles @ 66.2MPG
My Signiture below will have a new 5th FCD link tomorrow!

 

Hi Hot_Georgia_2004:

___And don’t forget to add that when you are on the pack for brisk acceleration, you have a nasty payback over many miles when the pack is charged back to a full SOC if that is the SOC you started out with! I would do almost anything to pull the pack out of the equation at times as it really can drag on my fuel economy when the BCM decides to conceal charge my Insight from a rather full 17 to 19 bars after an autostop over the next mile or so

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net

 

This is very true.
Past week or so my better half has been using my car instead of the Grand Caravan and tossing my numbers out the window. Once one of her trips were very low MPG (30's I believe) and asked her how she did that and she "Didn't know, just kept using the battery, that's what it's there for..right?"
I'm not good at explaining things so she always gets bored with explanations & tips.
She just likes to drive my little car over the G.C.

Anyway back on the topic at hand, it has been a challenge to make up for this.
You are truly correct about keeping off the Assist and have learned to try and keep off for the miles of recharging even a slightly depleated pack. On the hills typically Assist comes on at 36MPG (One bar below 40). But now, I guess for the warmer weather, hills that used to require assist I now can pull at 40 or 44MPG and have the same results, only not to use Assist and not have to charge for miles.

 

Forgive me.
I've been reading here for a few days.
I can't figure out what "driving with the load means".
Does it mean adjusting my speed so neither the assist or charge bars light as often as possible?

Also a lot of acronyms here.
A FAQ section may prevent newbies like me asking these annoying questions.

 

We're actually developing an acronym and FAQ section. In the process, so not to worry

Driving with a load, if I understand it correctly (as I just learned it, too?) is keeping your foot on the accelerator in the same position regardless of terrain. As you move uphill, your speed will drop and you'll pick it up again on the way down. This is making use of gravity instead of attempting to maintain an even speed and burning gas.

 

Hi Kenny:

___Yes, this one fuel saving technique is the holy grail of hyper milers as well as fuel economy hounds everywhere.

___Here is how it works … Let us imagine you approaching an overpass at 55 mph. The overpass has the same elevation on both sides with maybe a 25’ rise at the crest. Instead of applying more accelerator to maintain 55 mph up the incline, letting off the accelerator to maintain 55 on the decline, and reapplying accelerator at the finish of the overpass to achieve a steady 55 mph again, you simply lock the accelerator in the exact place that it was driving into the overpass. What you will see is your FCD’s instantaneous fuel economy stay at ~ the same spot as it was while cruising on flat and steady ground. At the crest of the hill, you might be doing only 51 - 52 mph. You must still maintain your accelerator at the exact same spot (lock it down) and let the car accelerate back to ~ 55 mph. What you will find is that by the time you have finished the decline portion of the overpass; your car will be at the ~ same speed (55 mph) as it was when you approached the overpass to begin with. It is a simple energy equation with a trade of kinetic (velocity) for potential (height) and that potential (height) is being converted back to kinetic (velocity). The sum should be ~ 0 without all the effects of an automobiles fuel economy being taken into account and you will see the payback in fuel economy hill after hill after hill.

___Remember the guy using cruise control? His cruise forced 3 separate changes to the accelerator angle to maintain 55 mph and 2 of those changes were fuel economy killers. I said 3 changes but in actuality, there were possibly hundreds depending on the reset rate and proportional band of the cruise (how sensitive) the cruise is. The big ticket item here is that you didn’t lose any fuel economy while traversing the overpass whereas those on simple cruise control dumped a whole lot of fuel for just a few scant seconds gained over your DWL technique in the process. This technique works in all cars but is quite easy to see with a game gauge in front of you.

___There are variations as well given not all hills have the same start and finish elevation. Some hills are simply to high to allow the bleed off to continue (climbing a 200’ rise over 1/2 – 3/4 of a mile will yield you 0 mph at the crest which is ridiculous in all actuality), traffic conditions don’t warrant a full blown DWL technique, or you are climbing a mountain. After all, you only have so much kinetic energy to play with … Each particular hill, overpass, underpass, mountain, etc. is different so you will have to let your FCD’s teach you what is best for each as you encounter them.

___Jason, you posted while I was typing this one up. Sorry for overriding your post.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net