The myth of pulse and glide Options

[WPWoodJr]

Here's an article on the myth of pulse and glide. You may not be getting as great an MPG boost from P&G as you thought.

[GaryG]

Here's an article on the myth of pulse and glide. You may not be getting as great an MPG boost from P&G as you thought.

There is no question P&G works great and you only have to look at my and many others lifetime MPG average at:
http://www.cleanmpg.com/index.php?page=gar...&maxnum=All

If it does not work for you, you're doing it wrong. The mileage you see us getting is from gallons of gas pumped divided by the OD mileage and in my case it's the lifetime mileage on my lifetime OD. You need to find an "expert" hypermiler in your area and have him show you how to do a correct P&G. Wayne Gerdes came to Florida and showed me how to do P&G in my '05 FEH 3 1/2 years ago and he would be an excellent person to show you P&G and a few other techniques in your FFH. I'm sure if you posted your location on CleanMPG you would find an "expert" hypermiler near you who would show you the correct way to P&G for free. At Hybridfest in Madison WI in about a week from now volunteers do "clinics" in all types of hybrids to help people learn these techniques. I'm sure even Wayne will be there and would love to show you the techniques in a FFH. He loves the FFH!

[GaryG]

Here is what I find interesting about MPG and you can relate P&G to hill climbing:

"Suppose a car goes uphill for 100 miles at 10 MPG and then goes back downhill for 100 miles and gets 100 MPG. What is the average MPG?

The car uses 10 gallons for the first leg and then 1 gallon for the second leg so the total fuel consumption is 11 gallons. Dividing 200 miles by 11 gallons results in 18 MPG, not the 55 MPG that would seem to make sense."

The thing about P&G is the pulse is much shorter than the glide in both time and distance. Gas versions of the Fusion must be Key-Off to get the benefits of P&G but the FFH has the advantage of EV mode to maintain speed and neutral glide engine Off for the glide.

The big difference in the glide verses neutral and "D" with the zero regen with slight accelerator pressure is that the Ford system is fast and you go into regen more than you think. This causes a less than acceptable glide for me than a neutral glide in EV.

Try this:

Drive in EV at 35mph just before an automatic restart at 40% battery SoC restart and apply the blip gas pedal for a restart. Accelerate back to 35mph at 20mpg to 35mph and maintain speed at 30- 45mpg till a EV shutdown and maintain 35mph till you need to shift to "N" for the glide in EV down to 30mph. Do the blip restart and accelerate back to 35mph and maintain speed again at 30-45mpg till a EV shutdown at 42% SoC. Repeat! You might just see better than 70mpg segments in your FFH.

[WPWoodJr]

There is no question P&G works great and you only have to look at my and many others lifetime MPG average at:
http://www.cleanmpg.com/index.php?page=gar...&maxnum=All

If it does not work for you, you're doing it wrong. The mileage you see us getting is from gallons of gas pumped divided by the OD mileage and in my case it's the lifetime mileage on my lifetime OD. You need to find an "expert" hypermiler in your area and have him show you how to do a correct P&G. Wayne Gerdes came to Florida and showed me how to do P&G in my '05 FEH 3 1/2 years ago and he would be an excellent person to show you P&G and a few other techniques in your FFH. I'm sure if you posted your location on CleanMPG you would find an "expert" hypermiler near you who would show you the correct way to P&G for free. At Hybridfest in Madison WI in about a week from now volunteers do "clinics" in all types of hybrids to help people learn these techniques. I'm sure even Wayne will be there and would love to show you the techniques in a FFH. He loves the FFH!

Thanks Gary, I wasn't questioning P&G, just commenting on a common mathematical intuition that is wrong. I actually saw this misconception at work here tonight and commented on it:
http://priuschat.com/forums/gen-iii-2010-p...html#post898857

I would love to get a lesson from someone. I'm in the Philadelphia area.

This post has been edited by WPWoodJr: Jul 9 2009, 10:50 PM

[nelsonlu]

Try this:

Drive in EV at 35mph just before an automatic restart at 40% battery SoC restart and apply the blip gas pedal for a restart. Accelerate back to 35mph at 20mpg to 35mph and maintain speed at 30- 45mpg till a EV shutdown and maintain 35mph till you need to shift to "N" for the glide in EV down to 30mph. Do the blip restart and accelerate back to 35mph and maintain speed again at 30-45mpg till a EV shutdown at 42% SoC. Repeat! You might just see better than 70mpg segments in your FFH.

I'm sorry, and I don't intend any offense, but that sounds like it requires a place with no traffic, no traffic lights, no stop signs, and no speed limits. It doesn't sound doable or legal in real life.

[GaryG]

I'm sorry, and I don't intend any offense, but that sounds like it requires a place with no traffic, no traffic lights, no stop signs, and no speed limits. It doesn't sound doable or legal in real life.

You don't do P&G IMO when it effects other traffic and that's the reason you pick your routes accordingly. There are however P&G techniques for all speed limits that improve mileage over what you would get driving down the highway with just the cruise control (CC) on. Don't get me wrong because there is a time and place for CC and I use it most likely more than most. After the pulse to your target speed I use CC to maintain a steady state speed while the HV battery is charging and continue when my FEH goes EV. Before the battery SoC drops to a restart of the ICE I shift to "N" for the glide. Now if there is traffic behind me I simply don't glide and just blip the accelerator for a restart and reset the CC at my target speed again.

In some States there are laws still on the books from a time before the automatic transmission and when brakes were not as reliable that you could not coast in "N" downhill. To improve fuel efficiency most automatics are designed to coast in "D" like you coast in "N" but the FEH and FFH will slow you down much more because of regen.. If regen was not programmed in "D" there could be problems maintaining the SoC in the battery in some road conditions. I spoke to a Ford Hybrid Engineer and he told me there are no disconnects between the traction motor and the drive wheels so there is no "N" gear, just a programmed strategy. Shifting to "N" eliminates regen and the traction motor/generator no longer provides charging or torque. For those that did not know it there is no reverse gear either. The traction motor spins the opposite direction to back-up the vehicle.

Everything here is doable and legal and Wayne Gerdes, Ford hybrid Engineers as well as race car driver Carl Edwards did use P&G to go 1,445 miles at over 80mpg with one tank of gas in the FFH. I'm sure they drove much slower than I do in traffic but I wasn't there to monitor. Also, my stoplights, signs, traffic and speed limits are the same as everyone else but I still take advantage of MPG when ever I can. There are times during my day I'm on a road that I can get 65mpg and also roads I can only get 40mpg. I just prefer getting 65mpg on roads with 35mph speed limits where I can use the best P&G and EV as much as possible. It just so happens I live near the Atlantic coastline and like driving along the beaches where many people drive slower than the speed limit for sightseeing. The police also monitor traffic (the girls) along the beaches which keeps traffic respectable also.

[GaryG]

Thanks Gary, I wasn't questioning P&G, just commenting on a common mathematical intuition that is wrong. I actually saw this misconception at work here tonight and commented on it:
http://priuschat.com/forums/gen-iii-2010-p...html#post898857

I would love to get a lesson from someone. I'm in the Philadelphia area.

Post a request on CleanMPG because I know if I lived near you I would love to show you what your FFH is really worth in MPG!