Tips for better MPG in your FEH/MMH.
1. Face Out: Back into your parking space in EV because the engine is going to run as soon as you restart to head out again. Gas is wasted backing up to change direction.
2. Use Electric Motors: During a cold start or after the vehicle as been parked for more than a few minutes, the electric motors will provide acceleration torque while the engine idles. Take advantage of the electric acceleration by NOT accelerating hard. Hard acceleration is always bad for MPG, and during the electric assist will break the idle of the engine sooner.
3. Avoid Routes With Stops: Even though the FEH/MMH will go electric to and at a stop, the energy (gas or electric) lost accelerating back to speed will cost you MPG. Our Town has recently started the use of “Round A Bouts” where you can yield with traffic at an intersection. These work great with timing the speed with traffic, and turning into the direction your going.
4. Pulse & Glide: P&G is an excellent way to save gas. Pulse is the acceleration portion of P&G. Glide is the coasting portion of P&G. About two years ago, I worked with Wayne Gerdes (the best hypermiler on the Planet) to find the best ways to accelerate (RPM wise) and glide.
Using a Scangauge instant MPG gauge, the factory Charge/Assist needle and the Nav. Sys. battery level, I found a number of factors to consider during the Pulse (acceleration) phase. The Scangauge “Load” gauge revealed that max load (99%) of the engine was at a very low RPM during acceleration. The electric motors start to assist the engine at max load which can also be seen on the Charge/Assist needle. So when the Assist needle begins to move to that side, the FEH/MMH engine is at max load. The bottom line is, when you accelerate to the point that the assist needle is in the assist position, your burning the most gas possible at that RPM and load, plus electric energy depending on the amount of assist. This energy loss is either coming from the HV battery storage or being diverted from the battery to the traction motor from the small generator.
What I’ve found to be the best all around acceleration was from using the torque curve for guidance and the Assist needle. Traffic permitting, I accelerate at 1800 RPM as much as I can. This means I hold the gas pedal so that I maintain that RPM until I get to my target speed. Traffic may require a faster acceleration, so the torque curve jumps to 2300-3000 RPMs for the best acceleration, but your going to get electric assist in that range. Stay out of 2000-2200 and 3000-3500 RPM’s where the torque curve is flat.
Pulse to your target speed, but remember the faster you go above 20mph, the gas mileage could be decreased. The best MPG seems to be using the P&G in the 20-35mph range. My best 20 mile round trip was 70.3mpg so far. When I’m on roads with faster speed requirements, I like going EV at the top speed of 40mph and gliding down to 30-35mph and holding at that EV speed until a engine restarts by a low battery or gust of wind.
All my gliding is in neutral with the engine on or off, but of course I prefer the engine off as much as possible. That’s All for now, any questions? GaryG
5. Climate Control: There are three coolant pumps in the FEH/MMH, two for the engine and one for the electronics which is for the DC/DC converter and eCVT. The A/C compressor also supplies two separate systems which are for cooling the cabin and the HV battery pack.
Lets start with saving MPG with one of the coolant pumps, because the other two you have no control of. There is no control of the mechcanical coolant pump which runs off the accessories belt while the engine is running or the electronics coolant pump. The one pump that can be controled is the heater pump.
Ford set-up the heater pump so that you can get heat from engine coolant while in EV. This pump will run in any position in the climate control setting other than off while the engine is off. This means this pump will run while you are even in the vent setting in EV. I turn the system off and save battery power when I can.
There comes point when the HV battery requires to be cooled constantly by the A/C compressor due to EV use and outside heat. At this point, cabin A/C should be used also. My choice is to take to the freeway and draft with the A/C running. More to come! GaryG
GaryG you are my hero! :D I've read your article on CleanMPG http://www.cleanmpg.com/forums/artic...brid--350.html many times and I'm still reading through the 9 pages of replies. Lots of useful info. I just got an 08 FEH. I know the 08's are built roughly the same mechanically as previous models but I believe the curb weights are different and so are the aerodynamics. Do you know if your findings apply to the 08's?
I drive on roads that are mostly 30-40 mph. If traffic permits, I accelerate from a stop at 1800 rpm's (based on your article). Is it better to punch up to 1800 or gradually build up to 1800? When no one is behind me I can be as patient as I wanna be!
When I get up to cruising speed, I do an FS which drops the tach to 1000. The hybrid monitor shows the electric motor is charging the battery and not using the engine. But the tach is not in the EV zone so am I still burning gas at that point? Aside from tapping on the brake, what's the quickest way to drop the tach into EV?
When coming to a stop at an intersection, what gives the most charge to the battery? Shifting to L and coasting, or dropping into neutral and using the brakes?
I'm finishing my first tank and I'm around 30 mpg in an AWD but I wanna get better! :)
I'd love to get my hands on the new '08 model and apply my techniques. My guess is the '08 FWD would do better than my '05 FWD. My concern would be if there was any changes in the regen area in "L". The '05 can get heavy regen which can heat up the system faster, but also charge the battery very quick. Ford may have adjusted this system to protect the HV battery more. Weight and better aerodynamics is always a plus for MPG, but I would drive it like having a lot of weight and poor aerodynamics anyway. The engine and eCVT are the same, but programming has been improved from what I'm hearing. All of my techniques should work with the '08, but some adjustments may be needed in the regen department with the fake shift (FS) in "L" gear if it has milder than my '05.
Originally Posted by sourpoodles
Always accelerate as slow as possible (traffic permitting) to get better mileage. There are three ways to go EV. The one I use the most is the FS in "L" at a speed above my target speed, but we know the FEH/MMH will not go EV above 40mph. I generally take the speed 3mph above the target speed for some regen to the battery just before going EV. A quick shift to neutral when you see the tach bounce is the best way to stop regen and coast down to your target speed and hold EV speed in "D". All braking should start by shifting to "L", and use the brake pedal from there to slow down. Good question about burning fuel during a FS. I only use the FS in "L" now, and this does not cut fuel unless you get a run-up of RPMs when the battery can't take a charge. However, the fuel use is greatly reduced during a FS, and your charging the battery at the same time. This is why I can push over 70mpg on good 30mph roads. You have the Navi with the energy screen to monitor the battery level like myself, which is great. I recommend the Scangauge 2 also. The HV battery will take a much faster charge at its lowest level, so this makes the FS in "L" allow you to go EV much sooner with a little SoC. The key to city driving is to stay in EV a longer percentage of time than ICE-ON charging the battery.
If you apply the brakes in neutral, you will not get any regen to charge the battery. If you are above 6mph, the engine can charge the battery with the small generator and WILL if the battery is not full. The only time I shift to neutral and apply the brakes is to prevent a run-up of engine RPMs. If I'm having a problem going EV with the use of "L" or the double tap of the brakes in "D", I shift to neutral and do light brake taps to go EV. It is very rare that I cannot go EV using these techniques. Cold and hot weather may require using the neutral brake tap to go EV also.
If you want better mileage, you and I want the same thing. If my techniques are not working for you, your not doing them right so ask for more details here. Your new '08 will get better mileage as rolling resistance decreases with mileage. You will be able to hold higher speeds in EV in do time, but you also can be getting much better than EPA on your second tank if you get serious about mileage. Without the use of the A/C, I was getting 37-40mpg just driving as much EV as possible when I first got my '05. Back then, these techniques I use now were not known. Take advantage of what we old timers have learned to start saving more sooner.
Maybe one way to give everyone an idea of how I can get the mileage I get is to explain my choices of techniques I use on my daily commute. If you have any questions about a technique or why I choose one thing or another, please ask.
There are three routes I choose from to get to the downtown WPB Courthouse which is about 20 miles all three ways.
1. A slower traffic coastal route with 29 stoplights, a few stop signs, a draw bridge, and the speed limit are between 30-45mph.
2. A faster route with not as many stops, but still no highway.
3. I-95 route with about 4 miles of city driving to get to and from I-95.
The slower traffic route from a cold morning start has yielded as good as ~51mpg, the other two around 46-48mpg. Depending on the wind, heat, time of day, and how much time I have, I make my decision on which route to take. When it's hot, the A/C compressor will run to cool the battery during EV use, so you might as well run the cabin A/C on normal recir. This will hurt the slower route mpg, so I make a choice between the other two routes based on needed store or other locations stops on my way back. Many times during the heat of the day, I-95 is the best choice with the A/C on a lower fan setting, and drafting a big rig. Drafting can be an art itself, and very unpredictable most of the time depending on wind direction and speed.
Since it's summer time and most of you use the highway for your commute, I take that choice for this post. If anyone wants me to continue another post with the slower routes, let me know.
From my driveway from a cold start on my 20 mile commute:
My FWD '05 FEH is sitting face out in my driveway. The battery is always low as that is how I always leave it the night before parking it. Get in and turn the key to the on position to adjust windows, Nav energy screen, and Scangauge to current trip. Remove my right shoe for feel of the accelerator pedal always! Check for clear traffic, start engine and shift to "D" to get moving ASAP. Even with a low battery SoC (state of charge), the battery will drop below the minimum 40% SoC to protect engine by using the electric motors for low to moderate acceleration. My first stop is within 130 feet to get on a 35mph busy street. Enter busy street and accelerate to 40mph, shift to "N" and cut engine by KEY-OFF and back to run right away to coast with the engine off, but keep all brakes and gauges operating. There is a light 1/4 mile away, so I try to time it for no stop. I accelerate by restarting the engine in neutral, shift back to drive as needed for traffic to 40mph and then shift to neutral and turn off engine again and coast to the next stoplight 1/4 mile away. There are 4 more additional lights which is a total of 6 to I-95. Most of the time, I do not need to do any Key-Off FAS (Force Auto Stops) past the first two stops because I can go EV with the LGA (low gear advantage). The LGA is a techniques of shifting to "L" and letting off the gas pedal to go EV.
At this point, my current average MPG is plus 35mpg before entering I-95 with a low SoC, so acceleration to 60-70mph is going to drop that average fast. Two lanes of a long On Ramp allows me to accelerate slowly (1800rpm) in the slow lane, faster it traffic requires. Always remember you can make up your average later with EV use, so don't sweat a quick drop in your average anytime during a tank of gas. If you've done a good job of your tank average so far, that small segment will not put a dent in your average tank MPG.
It all depends on a draft target, but I try to stay at 60-65mph till I get a choice rig. I constantly watch my RPMs to make sure the eCVT and engine is not getting carried away. This is where the right shoe off plays big time with your foot and brain. I play this game with speed to get the right slower moving rig in the slow lane to pass me, and speed up when he moves back in the slow lane to draft. These are the smart truckers who know speed hurts their mileage and driving record. After a couple of years of drafting, I know an an acceptable safe distance to draft back that most trucker don't have a problem with me. Without that wind load, the A/C does not add that much of a loss to MPG.
If I didn't say it, I constantly shift to neutral when there is no need to accelerate. Coasting in neutral allows no regenerative braking and less need to accelerate sooner, this means only a idle load of charging with the small generator. I do this during drafting. My average may be near 40mpg or better near the exit.
So now it's time to exit I-95 with a full battery. I could do a Key-Off FAS in neutral, or wait till I dropped to 40mph and go EV. The problem with Key-Off FAS is it takes 30 seconds before the computer will allow EV again. Sorry, I've mastered the techniques fairly well and know when to do what.
During my trip from I-95 to downtown WPB Florida, my average increases with lots of EV to the courthouse (two miles), remember I have a full battery at this point.
All of my tank MPG exceed 42 MPG and Most are at 45mpg or well above that number. The fact is, I've adjusted my driving habits, I came up with techniques to improve mileage and now I pay less at the pumps. This is all true everyday driving. Highway or city, the FWD FEH is a good choice, but it has to be a combination of the driver and the vehicle to make that happen.
It works for me everyday.
Now that I've made it one way downtown and am parked ready for my return trip, I decide I can take my time returning home and make up any loses from my cold start trip. One advantage I have is, all I do downtown is drop off completed work and pick up new work (5-10 min.) to take back home to complete.
Most of the time I'm paralleled parked and I leave my FEH to pull straight out. I do the same things regarding preparing the vehicle with the key on ie adjust windows and Nav energy screen and wait till an all clear with traffic and the next stoplight. Once the engine is started, the electric motors are providing power while the engine is at an idle again. I know I'll most likely stop at the next stoplight and the battery will have to low of a SoC to allow EV, so I accelerate (pulse) to a speed that will carry me there and do a Key- off FAS. If the light is green, I can always restart above 6mph to continue. As I get up to the 30mph speed limit, I do a fake shift (FS) in "L" to get the battery prepared for EV. It may take 3 FS to get to a SoC to go EV because the engine has been off and I've been coasting in "N" (no regen).
At this point, I begin P&G (pulse & glide) which is to accelerate to a target speed under 43mph and FS in "L" to go EV. Once the tach bounces, I shift to "N" for the glide as I go EV. It's all done at the same time to maintain speed the longest. As I coast down to 30-35mph (target cruising speed), I shift to "D" to maintain the flow of traffic in EV. When I get a restart due to a low SoC, I do a ~3-5 second FS in "L" which will slow me down ~3-5mph. I pulse (accelerate) to again a target speed under 43mph for the second FS in "L" to repeat the process above. Remember that if your slowly accelerating at 1800rpms, the small generator is also slowly adding to the SoC also.
I deal with stops by keeping an eye on the battery level. If the battery level is to low, the engine may come on during the stop which I avoid. To avoid this, kick the engine on before the stop to get a combination of the small generator and FS in "L" surge in the battery to go back to EV and prepare for a launch in EV from the stop.
There are roads that I must maintain the speed limit of 45mph, but as you can see, my battery is always low. This is no big deal because this speed will allow the battery to fill to the top for a long EV segment ahead. If the battery gets full with further distance to travel at that speed, I may start a Key-Off FAS P&G depending on traffic and conditions. This may call for a slow pulse to 50mph, Key-Off fas in "N" to 40mph, restart and shift to "D" to pulse again.
Pick and choose whatever techniques you feel comfortable with in the driving conditions your in. If your getting 30mpg tank averages, that may be fine for you. If you want to get 50% better mileage, that can happen also. My habits have changed, so everything is automatic when I get behind the wheel now.
I can get into much more detail on any of the techniques above if needed. Most of this has been repeated over and over by me, but I'd be happy to repeat it again.
You are Crazy
Gary, you are the man, but also crazy! You put so much effort into getting the most from your car. How much do you think you actually save in cash? Although i admit it is fum to drive that way, makes it a challenge. However, i cannot think that much when i drive...LOL
I love reading your stuff though, you rock!
I have been using almost all of the techniques, but can't seem to get more than about 34mpg for a tank in my FWD. All gas in Phoenix is 10% ethanol, it's hot and A/C is needed at least 6 months out of the year, and traffic flow is generally ~ 10 mph above any speed limit. I think that my battery may be losing some capacity as I can't seem to go EV for more than half a mile now, even with the climate control off. My best trip of more than 10 miles has been about 40mpg, but the trip below was about 2.5 miles, with probably 1.8 miles in pure EV.http://members.cox.net/carl.ebay/escape_mpg.JPG
DesertDog, that sound like you have almost the same conditions as I do here in South Florida.
First of all, you are flying in the dark without the battery gauge in the navi. Do you have a Scangauge? It will help you monitor each and every trip, day trip, yesterdays trip and your tank average throughout the refill.
Short trips under 5 miles will also hurt mileage as do all stop and go driving.
It is unlikely your battery is your problem because I have driven my battery very hard for 37,000 miles and it is slowly showing signs of use.
I do have the scangauge, which I purchased hoping to read the fuel pressure on a GM product, but no soap. The scan gauge is very cool, and I only had to walk two blocks from my house to buy one straight from the source! I do wish I had the nav system to see the energy screens, but I can't figure out if it can be easily added to an FEH that didn't come with it from the factory. The units turn up on ebay fairly often and only sell for around $350. Do you know of anyone who has added the nav unit to an FEH? Oh, and I have 71,000 miles on my FEH, so if you're noticing things at 37,000 I might be also. Also, I would like to add a light indicating when the A/C compressor is on. Sometimes the ICE kicks on when I think I should have plenty of electrons available to continue in EV, but without the SOC indicator I'm never quite sure.
Thanks for all your contributions regarding improving FE in the FEH. Without it I'd probably be getting closer to the 24mpg that my wife gets when she (rarely) drives it.