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Old 03-22-2006, 07:59 PM
GaryG GaryG is offline
Join Date: Mar 2006
Vehicles: '05 FEH FWD and '09 FEH FWD
Location: Jupiter, Florida
Posts: 1,092
Hypermiling the Ford Escape Hybrid ...

Gary G. - - March 22, 2006

Hypermiling with the Ford Escape Hybrid

FEH at its best in an all-city/suburban environment.

The FEH has many built-in benefits not advertised that can be used to increase fuel efficiency (FE). As with most benefits, there are drawbacks that need to be recognized or avoided whenever possible. Both the benefits and drawbacks I discuss are my own personal observations and have helped increase the FE in my ‘05 FWD FEH. This is not a complete list of ideas, but I hope it will assist you as we all continue to learn about the FEH.

In my opinion, the driver’s habits and skills play the biggest roll in hypermiling any vehicle. The EPA has set a high mark for city and highway ratings for the average driver to accomplish or compare other vehicles to. Many drivers feel that those EPA ratings are not realistic, while others look at it as a challenge to overcome. Let’s use the term “Hypermiler” as a person who can maintain FE above the EPA ratings.

The FEH stock gauges fall short in providing the driver with what I consider to be important for FE. The gauges I feel that should have been stock are: Battery Level, Digital Instant MPG, Engine Load and Average Trip MPG. Some of these gauges can be added as I did with a Scan Gauge for about $169, which plugs in under the dash. The Scangauge-II is now available which is much smaller, better looking and improved. Up until now, the high voltage battery level was only provided with the optional $2,600 Nav. System. The newest Scangauge 11 can now be programmed to read the HV battery State of Charge.

FEH - Standard Instrumentation.

The “Fake Shift” (FS) is a term I came up with to describe a benefit built into the FEH. Letting off the gas pedal as you would in a manual transmission to shift gears is where I came up with the term. With a sudden release of the gas pedal in low gear, two things happen. First, the rpm’s drop to near 1,000 rpm’s and lets the gear set move closer to overdrive to keep rpm’s low. Second, a big charge is being sent to the HV battery by the regenerative (regen) braking system (traction motor) The lower the state of charge (SoC) in the HV battery, the more charge it accepts. This is important to remember because the ICE uses much more fuel charging the battery with a low SoC via the generator/motor. The fake shift takes the load off the ICE and recharges the battery much faster to increase FE. This allows longer and the more FE electric driving.

During acceleration, the FS was used to lower RPM’s and allow the gearset to go to an overdrive ratio. Recently, I found going to a RPM range and holding that RPM till the eCVT finds the most FE way to increase speed is better. At 1800 RPM’s, I find this to be the most FE way to accelerate. This is not always an option in traffic or when you are in a hurry. The FEH’s torque curve between 1,800 and 2,500 RPM’s is very good with FE at 2400 being the next best choice to 1800 RPM’s. Holding the RPM steady and letting the eCVT change ratio’s to accelerate seems to be better on FE than accelerating to a higher RPM and Fake shifting. Looking at the torque curve for the Atkinson ICE, 3000 to 3500 RPM’s is almost flat and I would avoid that range for accelerating.

The “Low Gear Advantage” (LGA) is a term I came up with to describe another benefit of the FEH. If all conditions are right for Electric Vehicle (EV) mode, shifting to low gear (“L”) under 43 mph and letting off the gas pedal can cause the FEH to go EV at 40 mph. Just before the tach drops, it will make a slight bump which will allow you to know when to shift to neutral “N”) before EV. This helps for a smooth glide down to an EV speed you can hold in “D” (up to 37 mph in some FEH’s). This can also be used in combination with the Pulse & Glide (P&G) for the FEH. You can also preset the cruise in “D” at say 35 mph and increase the speed to 43 mph, shift to “L”, back to “D” at the tach signal and glide to the preset 35 mph in cruise. Anytime you are in “L” and let off the gas pedal, you get regen if the battery needs a charge. The fake shift in “L” will give you even a higher surge of charge.

Setup and Warm-up … The tire pressure I prefer in the stock Eco Plus tires is 50 psi, which is over the max sidewall of 44psi which you take at your own risk. Before even considering starting your FEH, I recommend setting all adjustments before starting her up. Turn the key to IG-II without starting up the ICE to provide power and then make adjustments to the windows, mirrors, gauges, etc. Last item will to include fastening your seatbelt of course. Wait for clear traffic, start the ICE, and move ASAP to begin warming up the ICE’s coolant and light off the CAT. This is the best time to recharge the HV battery since the ICE must run anyway until both the inferred CAT light off and Coolant temperature are reached which will allow the FEH to run in EV mode. During the warm up, the FEH uses the electric motors as a primary source to propel the vehicle for the first few blocks. The FEH/MMH has a built-in warm-up strategy to retard the timing and keep the engine at an idle while the electric motors provide torque and vehicle acceleration. If you allow the engine to maintain this low idle during warm-up, the cat converter will heat up faster and reduce harmful emissions and reduced the time to go EV. If you accelerate and increase RPM's, you will prolong warm-up and EV time. A few “FS” in “L” at 30 mph will aid in getting the battery SoC back up to an acceptable level for FE. Once the battery level is up after the first few blocks, I accelerate under 90% load to speed and shift to “N” and glide as traffic permits. I drop her back in “D” and Pulse back up to speed slowly. Repeat. There is no regen in “N”, but the ICE can still turn the generator/motor for charging. If the ICE takes awhile to warm up, I use fake shifts in “L” to speed up HV battery recharge and maintain low rpm’s (below 2,000). If warm up is expected to be quick from a restart during a just driven segment on the same day, a fake shift in “L” may be needed for a low battery to start EV mode quicker. The electric motors will still be primary for the first few blocks if the FEH has been shutdown for over five or ten minutes because of this warm-up strategy.

Highway driving is something I avoid, if possible. If you drive on the highway, try to stay at the max speed at 1,800 rpm’s (60 - 65mph without a headwind). If you have the Scan Gauge, drafting is a perfect way to find and maintain the best FE. On average, a good draft can yield 45 – 55 MPG at speeds of 60 - 70 mph. It’s not uncommon to see over 70 mpg during drafting. There is a safe distance to maintain which large truckers don't mine, so up close drafting is not required.

When descending overpasses, I have seen as high as 200 MPG on the instant readout. Many hypermilers that drive other vehicles would not think this is possible, but it’s the way Ford set up the Atkinson 2.3L to handle higher speeds. Take away wind resistance in the FEH at highway speeds and it cannot be beat IMHO. During hot weather where the A/C is a must, take to the highways and draft safely. The A/C does not affect FE that much when drafting. Learn to expect > 43 MPG averages when driving on the highway. Gliding in “N” with slowing traffic and off ramps needs to be considered to maintain speed when needed. Gliding in “N” with the ICE running can give you a 38% improvement over gliding in “D”. As soon as you drop below 43 mph on any slow down or stop, use the LGA (shift to "L") to drop out the ICE completely.

High percentage highway driving - Near maximum FE expectation.

High percentage city driving - Near maximum FE expectation.

The fake shift can be regulated at the lowest SoC of the battery and maintain EV mode with a yield of an average > 60 MPG. In fact, the HV battery accepts a faster charge at its lowest SoC limits. This reduces the travel distance and time with the ICE running and increases the travel distance ratio in EV mode. In other words, instead of going 1.3 miles in EV until a low SoC starts the ICE, and then going 1.8 - 2 miles to recharge the HV battery in normal conditions, the opposite happens with a low SoC and the fake shift in “L”.

An example of this method would be as follows in 30 – 43 mph city driving:

Take the FEH to 43 mph no matter what the SoC. Shift to “L” and go EV at 40 mph as stated earlier and then shift back to “N”. Glide to an EV speed of your choice, shift back to “D” and hold as appropriate. DWL (Driving w/ Load) can be an EV mode enhancer when and where appropriate. When the ICE starts due to low SoC, slowly increase speed with one fake shifts while in “L” to 43 mph. Letting off the gas pedal in “L” will be your second fake shift before going EV and shift to “N” for the glide to your desired EV speed in “D”. After the ICE starts, repeat this scenario for as long as traffic allows. The distance in EV should far exceed the distance with the ICE running if properly performed. The fake shift in “L” can work anytime below 41 mph to go into EV and can reduce the ICE run time after a restart. Never worry about the battery SoC except for climbing hills and constant speeds above 40 mph. Use the fake shift to fill the battery instead of putting the load on the ICE when and wherever possible.

Steady state speed FE

Besides the various techniques to improve the FEH’s around town FE, her steady state FE capabilities are very good in their own right. All tests were performed over a 1.0 mile distance with tire pressures set to 52 #’s in mid 90 degree F temps.

Scan Gauge - constant speed tests - MPG Results

With Cruise Control    
RPM’s1,1001,5001,5001,600 - 1,800
Run #30 mph40 mph50 mph60 mph
156.8 mpg56.2 mpg51.2 mpg42.0 mpg
262.3 mpg56.0 mpg51.8 mpg42.5 mpg
357.8 mpg56.0 mpg51.1 mpg42.5 mpg
Average’s59.0 mpg56.1 mpg51.4 mpg42.3 mpg
Without Cruise Control    
RPM’s1,1001,5001,5001,600 - 1,800
Run #30 mph40 mph50 mph60 mph
161.2 mpg60.5 mpg52.8 mpg44.0 mpg
256.9 mpg58.3 mpg50.2 mpg44.3 mpg
363.7 mpg57.2 mpg44.3 mpg42.8 mpg
456.7 mpgNANANA
Average’s59.6 mpg58.7 mpg49.1 mpg43.7 mpg

The differences between using CC or not at the above test speeds on an absolute flat roadway with no traffic interaction are statistically insignificant in the FEH.

Important: Many of us drive in low gear ("L") thinking we are in the same state as drive ("D"). During my tests, I accidentally left the shifter in "L" and came up with astounding results. It appears that "L" at below 50 mph, there is still regenerative braking occurring while in cruise control. This must also be the case while not in cruise control. The result I was getting was a 5.1 MPG reduction at 30 mph while in the "L" position over the "D" position. At 40 mph, I was getting a 4.1 mph reduction in "L" over the "D" position. To sum it up, I will no longer be using the "L" position in the steady state cruising mode. In addition, I believe that using "L" in EV mode may reduce fuel efficiency. This is sort of like saying the "L" position causes an accelerate or brake (regen) "L" mode, instead of an accelerate and (light regen)"D" coast mode. Based on these test, I recommend using "L" for going EV and charging the battery only. Driving only in "L" will reduce your FE.

Still the best SUV available at this time

This is a great SUV, learn how to drive it and get the most MPG possible!

Last edited by GaryG : 10-09-2007 at 02:27 AM. Reason: Added more information to extract the most out of the FEH.
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