'09 FEH Techniques

Discussion in 'Ford Hybrids' started by GaryG, May 21, 2009.

  1. GaryG

    GaryG Well-Known Member

    After 10 months and 11,000 miles with my '09 FEH I thought I'd share some easy techniques I'm using. I have two SGII's in my FEH and monitor SoC, Instant MPG, LP and LOD on one and Tank MPG on the other most of the time.

    By monitoring SoC % I know when to go EV and when to restart the ICE with the blip of the accelerator pedal. On flat roads I use the cruise control to get the best MPG under 50mph. If possible, I shift to "N" at about 40.8% SoC for a glide as the HV battery drops near a restart (40.1-40.4%) and then shift back to "D" for the blip restart. The blip restart prevents an automatic restart that causes a big drop in the SoC. Shifting to "N" cancels CC and provides the longest glide with a slower drop in speed. P&G works best for me with 35mph on the high side and 25mph on the low side.

    I've found that pulsing up to speed at 80% engine LOD and letting the CC maintain speed while SoC builds is the best. The Instant MPG is much better in CC than I can maintain and it's not uncommon to see an Instant 30-45mpg while the ICE and generator bring up a 40.8% SoC. In general the best Instant MPG while under heavy charging is above 30mph and below 45mph. When I'm above 32mpg Instant MPG while charging in CC I will let the ICE continue to charge the battery for a longer EV segment. This is when for some reason the ICE still is running and not dropping into EV mode under CC. It could be due to a slight up-grade or a headwind but I take advantage of the good MPG while charging the low battery.

    I monitor LOD for ICE acceleration and climbing large bridges. Climbing bridges I try to maintain or slightly decrease speed while maintaining RPM between 1,500 - 1,800 and LOD less that 88%. I go EV at the top and shift to "N" to increase speed to 40mph and hold 40mph with "D" and light regen with the brake pedal to build SoC. At the bottom of the bridge at 40mph I shift back to "N" to a point I need to maintain speed in EV with CC.

    I monitor LP (Open/Close Loop) for fuel-cut. Open Loop and a 9,999mpg Instant MPG reading on the SGII means I'm getting full fuel-cut. Under 40mph the '09 will go 100% fuel-cut during decel in "L" but it's rare that I use that because of better regen by using the brake pedal.

    I monitor Tank MPG to not lose control of my tank goal. Highway driving lowers tank MPG so this helps me limit just how much highway driving I should do to meet my tank goal.

    Let us know what works and does not work for you!

    Last edited: Jun 19, 2009
  2. testdrv321

    testdrv321 Member

    LP = ?
    LOD = ?

    Do you know the double tap trick? Once you get under the mex EV speed, double tap the brakes, very gentle and very quick, and it will shut off the ICE.
  3. GaryG

    GaryG Well-Known Member

    The Scangauge has many standard gauges and LP displays OPEN LOOP or CLOSED LOOP. Open-Loop is an operating condition based on instructions not modified by PCM feedback. Closed-Loop is an operating condition or mode which enables operation based on sensor feedback. You see Open-Loop during engine warm-up, EV, Fuel-Cut or Wide Open Throttle
    when fuel is either off or not being regulated by sensors and the PCM.

    The Scangauge can also display LOD which is calculated Engine Load percentage with 99% or 100% being full engine load.

    The brake pedal double tap was one of the first things discovered by new FEH owners in '04. I discovered the use of the double tap in neutral to go EV when the electric system gets to hot or the battery will not warm-up in cold weather. The neutral brake pedal tap removes regen braking from the traction motor which blocks conditions for EV. With the new '09 FEH system these tricks are no longer required to go EV at or under 40mph.

  4. GaryG

    GaryG Well-Known Member

    With this last drop in my tank MPG to 49.4 I began to experiment more with a harder acceleration during P&G. The A/C compressor is running much more now due to 90 degree plus heat to cool the battery. I can tell when the compressor is on when I'm at a steady state speed using the cc by watching the drop in instant MPG. What I discovered with accelerating at a higher engine load between 83 - 90% was an overall increase in MPG with a longer cc steady state speed recharging the battery. The '05 FEH just pulls too high of a RPM trying to accelerate this hard but the '09 handles the torque much better and more efficient. We'll see at the end of this tank how much the harder acceleration helps during P&G. This could be another breakthrough for higher MPG averages for the '09 FEH.

  5. GaryG

    GaryG Well-Known Member

    This last tank confirmed that the increased in acceleration has countered the lost in MPG by the battery A/C somewhat. I didn't expect to exceed 50mpg during the hot months here in South Florida but this change in the P&G technique should also improve my winter months MPG. Instead of using just LOD I'm controlling the pulse more with Instant MPG now and got that idea reading Bill Wood's article "The Myths Of P&G". This brought me back 3 1/2 years ago when Wayne was telling me to test for the Pulse in my '05 FEH on Greenhybrid. I'm not positive but I could be hitting 55mpg tanks when my weather cools off. This means tanks at almost 170% of combined EPA estimates with E10.

  6. rmcmast

    rmcmast Well-Known Member

    I may have made a discovery when my 2009 FEH is under 46 SoC and I cannot get fuel cut when coasting over 40 mph (this was discussed in a different thread but I thought it might be more appropriate here).

    The last couple of times this happened to me I tried the old double tap technique on the brakes. Speed was around 50-55, SoC around 45, no fuel cut. Then when I double-tap I immediately go open loop/instant mpg 9999 on the SGII.

    Gary, Can you check this out sometime?


    Last edited: Jul 18, 2009
  7. rmcmast

    rmcmast Well-Known Member

    Just a quick update to my previous post. One very light tap on the brake seems to do it. Today I was coasting on the highway with SoC around 45. No fuel-cut, but one light tap and the SGII went instant mpg 9999/open loop.

    -- Rick
  8. GaryG

    GaryG Well-Known Member

    That makes sense Rick, I was just about to post I get Fuel-Cut below a 46% SoC but not all the time. It even happen today and as I remember I did slow with the brake pedal in "D" and was waiting to slow to 40mph for EV mode when I noticed above 40mph I was in fuel-cut with a SoC below 46%. This has been a tough nut to crack but I think you've done it!

    Since I seldom get above 46% in city driving I can make real use of this information. An example is now I use EV DWL climbing bridges (break-in) and have a low SoC at the crest of the bridge. If I exceed 40mph on the downhill and get a restart I can get fuel-cut in "D" with regen till I go EV at 40mph and finish the glide in "N". I'm going to play with this and report back any issues. Now I can take that sticky note reminder for 46% SoC and fuel-cut off my dash. Good find!

  9. rmcmast

    rmcmast Well-Known Member

    The brake tap is really working out great for me. We live outside the city and when I can travel the back roads I can EV longer, let SoC get lower and still coast down longer hills over 40mph with fuel cut. I'm climing better in EV on small hills. Today I made a run for gas for the tractor: 7 miles at 56mpg! Only 42 on the way back though since I took the highway back.

    -- Rick
  10. Xringer

    Xringer Older Member

    Hi Rick,

    My warmed up idle TPS is 12, so I've got the cut-off value set to 16.

    Is cutoff at 16 what you are using? (Since we have somewhat similar engines).
  11. rmcmast

    rmcmast Well-Known Member


    I have my SGII cutoff set at 18. When warmed up my 2009 FEH's TPS is 14 when gliding with my foot off the accelerator (ICE on).

    -- Rick
  12. Xringer

    Xringer Older Member

    Thanks, that's pretty close, considering.

    I wonder what kind of MPG you are seeing for highway only driving in the 55 mph range?

    Mine is doing really well on the highway. I think if I really work at it, it could hit 40 mpg highway.
    This little truck is amazing me.. :woot:
  13. rmcmast

    rmcmast Well-Known Member

    It's still getting broken in, but usually high 30's or low 40's. Depends on the conditions. On the interstate I usually cannot get away with 55mph around here and usually go 60mph.

    40mpg for a gas Escape would be very impressive! Our old 2005 4cyl gas Escape only did around 21-24mpg, but that's before I started hypermiling in 2007 when we traded for the 2007 FEH.

    -- Rick
    Last edited: Jul 21, 2009
  14. Xringer

    Xringer Older Member

    Thanks for the info. You have pretty much confirmed my theory,
    that there isn't a lot of difference in FE between the 2009 FEH and
    the 2009 Esc 2.5I/AT at highway speeds..

    I've been reading about some good mileage on the Fusion 2.5I/AT cars
    and I'm thinking maybe they also might show a similar FE compared to the FFH,
    at highway speeds only..

    I wonder if Ford would get upset if MotorWeek did a side-by-side Escape 65 mph road test?
    If the MPG came out the same.. :eek:
  15. GaryG

    GaryG Well-Known Member

    The brake tap is working great for me also above 40mph for fuel-cut with a low battery SoC. It's funny how this simple technique works instant as soon as you tap the brake pedal. I just got to add it to my bag of tricks and use it till it becomes a habit like the accelerator blip is for me now.

    Xringer, the best way to compare the '09 FEH and '09 I-4 gas Escape highway MPG is with the same person IMO. They are still completely different systems and a skilled FEH driver should be used because they would know also how to drive the gas Escape 6 speed which is less complicated.

    My '05 FEH got 45mpg on a 100 mile trip between 60 - 70mph on I-95 which included a cold engine warm-up. The funny part was the MPG was still getting better as I added miles. I did the same trip in my Dads Towncar and got 32mpg with the A/C On. The big problem with I-95 is the slow bumper to bumper you run into without the hybrid. That said, you got a great set-up with this 2.5L and six speed auto but after 15,000 miles your going to see a mark improvement in MPG when she is fully broke-in. That six speed can also be flat towed like our eCVT in neutral which can also have some MPG advantages.

  16. Xringer

    Xringer Older Member

    15,000 mile break in?? Holy cow! I'm not sure I'll still be driving much when 15k rolls around.
    I was shocked when I heard the 'real' break in was 3 to 4 thousand.. But 15k?? WOW!

    Since I only drive 1 or 2 thousand miles a year, nowadays (being retired) that break in is too long.
    I'm going to have to start driving back home to Texas a few times each year to get on some miles! :)

    "'05 FEH got 45mpg on a 100 mile trip between 60 - 70mph on I-95" Dang, that's great.
    I'm pretty sure I'm not going to be seeing much over 40mpg.. But, I have seen it once,
    just for a minute, before I got behind a very slow truck taking the same exit
    I was using for a turn-around. A few minutes later, I was in heavy traffic and getting 38 trip average..

    The ICE does pretty well in the city if there aren't any red lights are stop signs.
    Many times on a flat section of road when I'm going 35 MPH, I'm seeing better than 35 MPG..
    Wish I had a flat track to see what the optimum FE speed was.. That would be an interesting experiment..
    Right now, 53 is one of my favorite CC settings. Very relaxing cruising..

    Drive carefully,
  17. GaryG

    GaryG Well-Known Member

    You can see my steady state speed results here http://www.cleanmpg.com/forums/showthread.php?t=350 at 60mph. Of course I use many high speed techniques in neutral with P&G to boost those results in highway driving normally.

    When I say 15,000 miles I'm talking about when coasting in neutral got to its best in my '05 FEH and I can already see my '09 FEH at 12,500 miles is right on the same target as it's getting better. You need to do a steady state speed test like Wayne instructed me to do a few years ago on your '09 Escape and compare. I need to do the same on my '09 FEH and add it to that article when I get a chance.

  18. rmcmast

    rmcmast Well-Known Member

    One thing I notice when it goes into fuel-cut is slight drop in RPM (drops from 1100 or so down to 1000). It's similar to the tach blip when the FEH drops into EV. Any idea what causes the RPM change?


  19. GaryG

    GaryG Well-Known Member

    When you think about it, fuel is cut in both conditions and the electric motors take over engine RPM for a smooth transition for NVH. For EV, the RPMs drop to zero slowly but for fuel-cut the motors are holding the RPM steady because fuel may again be added for acceleration at any time. This is why (I think) the blip works to reduce the motors from adjusting the transition from EV to a steady take over of engine power. Holding the engine RPM at 1,000 in fuel-cut allows a smooth return to acceleration as fuel is added. The blip from EV prevents the smooth transition and saves battery SoC. The question is do you want a smooth EV to restart that cost battery SoC or do you want max MPG by using that SoC for a longer EV distance later?

  20. Xringer

    Xringer Older Member

    I had seen your chart before "Scan Gauge - constant speed tests - MPG Results"
    and looking at it again is making me think my CC is going to be my best friend..
    And, I now have a goal to shoot for. On a flat track, 50 MPG at 50 MPH.. :)

    Now, I have to go find somebody who has been hypermiling a Ford like mine,
    or maybe a new Fusion with the 2.5L w/ 6sp AT.. I'm really curious how the
    6F35 works if you slip it into 'N' while going down a hill..

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