Rich, the reason for my statement is "L" does not promote coasting. While you and I can hold the pedal in "L" so that it gives you a coasting effect, its not giving you the ease of coasting that "D" or "N" does. Trying to coast in "L" is a lot of effort to get near the FE you get with "D" and "N".

There is no question I give up FE when I use cruise in EV for the same reason, it does not promote coasting. Sure, I get no arrows in EV cruise when I start to glide down a hill, but can't coast below the cruise setting. My reason for giving up some FE in EV cruise control is like you giving up FE by staying in "L". We both have our reasons but both have a negative effect on FE.

Since I got the scangauge, I have been able to see better what coasting does for FE. Never cared much for the instant bar graph on the nav. sys. which max at 60mpg. Letting off the gas and coasting gets you anywhere between 60-350mpg while the ICE is at Idle. Most of my readings at around 35mph are over 100mpg coasting. On the highway, coasting can give you readings of 200mpg and more.

Where your and other's FE picks up in driving in "L" is below 40mph because of going into EV without any effort of remembering to shift or do a double tap when you let off the gas. The problem comes with a over charged battery and no shut down till you stop for a few seconds. We all agree that while the RPM increases from the generator, its not using much gas. A reading from the scangauge instant mpg could comfirm this the next time it happens to me if I can think of it.

With my respect for xcel on FE, I couldn't understand why he didn't post or give me his opinion on my EV cruise driving hurting my overall FE. He must think I understand there are trade off's. As far as giving my opinion on driving in "L", it's not to bash anyone for their driving style. What my intent was to point out how I strongly feel that coasting as much as posible, is the best way to get the the best FE out of any car.

Simply put, IMHO, driving in "L" is to much of a trade off for me at any speed in any conditions. Driving in "L" can help others get better mpg averages, but not me.

GaryG

 

But if coasting down a hill increases your speed above 40MPH, the engine must start to prevent the generator from overspeeding. Then you go from 999MPG to your stated 60-350MPG. I'll take 999 any day. I acknowledge that driving in low on the highway gains you very little, but it also doesn't really hurt anything and as long as you don't mind fine pedal control, it allows you more control over the motor/generator. We all have our preferences and our circumstances are different so we all need to find what works for each of us. Gary certainly turns in some impressive numbers so his methods obviously work for him.

 

Scott, your missing my point completely. By being in low with a full battery, you continually slow the FEH down when you let off the gas pedal any at all. If you need to slow down with a full battery, coasting with no gas pedal will slow you down also. Why would you want to slow down and burn energy you can't store or use and then use more gas to regain lost speed? This is like constantly being on the gas or brake all the time. Do you ever slow and coast to a stoplight hoping it will turn green before you have to stop completely? If your not, your missing mpg FE and chances are you'll never see numbers like mine. This is true at any speed and I try to even coast (traffic permitting) before getting to an off ramp from the freeway. This is the best way to save gas because your battery is always full at this point. Every time I drop below 40mph and don't need a charge, I coast in EV. This is when I use the double tap instead of "L" to go EV. BTW, the scangauge shows 9,999mpg, not 999mpg in EV and if I go down a bridge or hill, I try to stay in EV and under 40mph with "L". If I could reach speeds of 45 or more on a down hill, I'll take the coast with the ICE and wait for EV at 40mph and coast as far as posible.

Good gas, coasting and EV are needed to get to my numbers. I don't see any other way around it. The scangauge helps very much on highway driving now and a long trip may prove the FEH can get far better than the EPA highway stated.

GaryG

 

Gary, I do get your point. I'm not trying to contradict what works for you. As I said, our situations are very different. I rarely have the opportunity to let the vehicle coast. I commute 60 miles and most of that has pretty heavy traffic that frequently slows fairly quickly so if I don't use low gear, I'm stepping on the brake. Both do the same thing and I don't always have to actually step on the brake if I'm in L. That combined with the rolling hills and cold temps now make it rather difficult to even reach 30MPG this time of year.

When I get closer to home and the traffic thins out a little, I do try to anticipate lights. Rather than just take my foot off the gas, I use the pedal to acheive the same effect. My point was that anything that can be done in D, can be done in L with pressure on the pedal. I happen to disagree with the blanket statement that leaving the shifter in L is bad for FE. It all depends who's driving and what their driving style is.

I'm planning on getting a Scangauge as well and we'll see what I can do with that.

 

I'm going to reply to posts of about 1 month ago.
Many people report that "Low" makes the ICE rev more now that it is cold.
I'm not sure people understand why.
Many people say that when the ICE rev's coasting in Low, it's the motor/generator spinning the engine to use up excess electrical power. I'm not sure people understand this is false!

If you know what I'm taking about, sorry, skip to the next message.
I hope some of you will appreciate this info.

First, why does the ICE come on more, and rev more when you drive in Low when it is cold???

Answer: A cold battery has a slower charge / discharge rate.

When the battery is at 75'F, it can put out 25,000 watts to the wheels, and it can take in 25,000 watts from the generator ( regenerative brakes or ICE ).
When the battery is at 25'F, it can put out or take in only 10,000 watts.
When the battery is at 0'F, it can put out or take in fewer than 5,000 watts.

At 75'F you have 25kw of braking effort, or about 34 horsepower.
At 25'F you have 10kw of braking effort, or about 13 horsepower.
At 0'F you have 5kw of braking effort, or just 7 horsepower.

The programmed function of "low" is to slow the car down, not all this Regen we've become accustomed to. So when it's cold, the generator / battery combo CANNOT slow the car down as well as it can at 75'F, so the ICE spins sooner, and more often to provide the braking effort. Of course it works both ways.
The table above also shows you just how little assist you get accelerating when it's cold outside. It's not a fault of Ford, it's a law of Physics.

Second. When going down a hill, and the HV battery is full... The regen QUITS altogether.... it does NOT keep manufacturing electricity, and "bleed it off" by spinning the ICE. It's much more simple than that.
When the ICE rev's up to high RPM, the WHEELS are spinning the ICE.... The ICE acts as a giant air compressor ( without gas going into the cylinders ), and provides the resistance, or "drag" to slow the car down.
The ICE may spin up even if your battery is NOT full, if the wattage required to slow you down exceeds the amount it can accept from the generator at any temperature. Under these situations, it is possible, though the ingenious power split device ( aka eCVT ) to get a % of slowing from regen and a % of slowing from engine compression at the same time.


Hope that is helpful to someone.

-John

 

Okay, then why does the ICE continue to spin at 3-4000 RPM AFTER the vehicle has come to a complete stop, almost always when stopping on a hill? Sometimes it will stay up there for 5 or so seconds. Where is this power coming from? The wheels certainly aren't producing it. Is it burning gas or electricity? Or both?

I have two of these and they both do it.

 

Don't know if this was directed to me, but it *was* helpful! Thank you, and sorry for any misinfo I may have spread.
C.

 

Ray, I agree with John on most of what he said except what you point out also. My understanding is there is a one way clutch that would prevent the wheels from turning up the ICE. As you point out, if the wheels are not moving, how is this posible. As far as not burning any gas, I agree with Sweetbeet and the instant MPG reading on my scangauge shows mpg being used and very's on the RPM the ICE is turning up while stopped at a light. The question would be if the PCM could shut off the fuel injection system and if fuel could be sucked out anyway on the intake stroke. For emission sake, I don't think Ford would have the PCM stop a spark to fire the gases either. My guess is that the run up is coming from the same path as the starting system from the HV battery. After all, the engine is being started during this process.

GaryG

 

A direct answer to a direct question in a large group setting at the Ford Hybrid Experience in Dearborn, October 2005 was like this:

Q: Under what conditions is fuel totally cut from the ICE?

A: ( from Ford Engineer ) Whenever the ICE is instructed to ramp up to provide compressional engine braking, the fuel is totally cut from the engine. No fuel is being used. Some of you who drive in Low gear have noticed this effect. This effect is normal and will not harm your vehicle.

I have a direct answer that fuel is not being used during the ramp up to high RPM.
About what is spining the ICE.... that is a bit vague.

However, mine NEVER EVER maintains a high rpm when at rest.
In fact, whenever I'm coasting down in low, and drop below 10 MPH, the rpm's drop to the normal 1000 ( gas kicks in ) or the car drops into EV mode.

If your does, sounds wierd. Did you have a very early build date?
Mine was December, 2004. Early, but right after the first, and only software update. ( That I know of ) And who knows if that "update" would have anything to do with what we are talkin about.

It is facinating to me, for months now, how something that is mass-produced, and supposed to be identical, can vary from place to place.
I CAN'T ( sort of running the car in park ) get less than 30 MPG. Ever.
And some can never get up to 30 MPG. Why is this?


-John

 

Well, if there is no gas fuel being burnt, the answer can't be too vague. There is electricity being consumed. A scan gauge will answer one way or the other. Haven't got mine yet.

I must have two weird vehicles then. Got the '05 in late March '05 and the '06 in June of '05. I don't think the '06 would be considered an early build. I doubt it is a coincidence that they both do this. Only difference is the '05 seems to rev slightly higher. (4000 vs 3500 max.).

No two things are identical. There are tolerances in manufacturing and variation between parts that could account for some difference. If I remember correctly there are also differences in the programming between the CA type emission vehicles and the non-CA vehicles.