I don’t own a FEH/MMH yet. But after reading and doing some research, this is the vehicle I've settled on.

So I decided to rent one for a day or two and drive my regular drives to see how it worked out. I have never driven a HV before this, and the test drives from the Ford dealers were much too short and controlled, and I didn’t get to drive on roads that I am familiar with.

Background: I rented an ’09 FEH FWD. The temps on day 1 were in the 12 to 35 degree range. The day started out in the mid teens, I drove to an area where the temps stayed in the teens all day, and then on the return drive, temps 'warmed up' to the low 30s. On day 2, temps were in the 35 to 45 range. On day 1 I put about 200 highway miles on the vehicle, on day 2 I did about 50 city/suburban miles.

Main observations and questions:

• Didn’t get the stated highway MPG (28 Hwy, 32 City). Mine combined was 27. Highway was 25-26, City was probably 30+. This is based on the readings on the readout in the instrument cluster. And confirmed by the miles and fill up before returning the vehicle.

• EV Mode. The battery was not able to accelerate the vehicle much at all. It took a while to learn that turning off the heating system (via the fan switch) seemed to be the most effective way to make the most of the EV mode. I read about the ECON mode on here, and so kept it in ECON mode for the first day. Since I did this in late January, and the outside air temps were in the 15 to 20 degree range on the morning of day 1, the heat was needed and I didn’t even think to turn the heating system off completely.

• Accelerating/starting out from a complete stop from a stop sign or a red light: To keep up with the other traffic, the ICE would always turn on. I was never able to accelerate at a normal, reasonable rate on battery alone. This is the one item that surprised me the most. In hindsight, I assumed I’d be able to accelerate up to 20 or 30 MPH from a dead stop on battery alone. This was on roads that were level and smooth. When going up any incline whatsoever, even a small one, the ICE came on virtually instantly as soon as I touched the gas pedal.

• Never ever got past 30 MPH on the battery alone. In fact rarely got past 20 MHP on battery alone. One possible an exception to this was were when going downhill on an incline.

• Questions for other FEH/MMH owners: How fast can you go on EV mode? Can you pull out from a stop sign and get your vehicle up to 40 MPH? Up to 30 MPH, or up to 20 MPH? Under what conditions exactly can you cruise along down a road on EV mode alone?

For me to accelerate at a reasonable and normal rate -- fast enough so the people behind you don’t honk their horns, flip you off, pass you out or otherwise become impatient – I was never in ‘EV only’ mode and the ICE came on almost always.

Cruising around a shopping center's parking lot was about the only thing I was *almost always* able to do on battery alone.

The battery to ICE switch over is very sensitive, after driving for two days, I’d now describe it as hyper sensitive to almost any pressure on the accelerator\gas pedal whatsoever. I saw this as a trade-off between how light you can press on the gas while still maintaining a reasonable acceleration so as keep going with the flow of traffic. See the comment above about this being the one item that surprised me the most. After the two day test drive, I’d say I was never able to pull out from a stop sign or a red light fully and completely on battery alone. Except perhaps one time when I was facing a steep downhill incline from the stop.

I also sort of did a comparison with a Prius today.

On a drive today, I saw a Prius pull up alongside me. I got behind him/her, and noticed some exhaust or water vapor coming out of the tailpipe for a few seconds, then the exhaust stopped. I took that to mean the ICE was running. Since I was experimenting with the FEH pulling out from a stop at a red light, I decided to do a crude comparison and followed the Prius in stop and go traffic – a few miles in a road with a traffic signal every 3 or 4 tenths of a mile.

Every time I saw smoke coming out of the Prius exhaust/tail pipe, I assumed it’s ICE was running. For one or two lights, the Prius did seem to use the ICE to accelerate, but after the first one or two lights, the Prius seemed to run entirely on its battery in accelerating from all the remaining red lights. In comparison, the ICE on the FEH I had always kicked in a second or two after starting out from a light. Note that I was keeping up with the Prius here, not going any faster or slower, and just observing how the FEH worked. This lasted for about two miles, then we both went in different directions. I suppose this is a crude way to test. But I have heard and read so much about Toyota and the Prius leading the way in hybrid technology.

Any comments, or answers to the above questions are appreciated. Especially on the ‘how fast can you go on EV mode’ question.

 

Hi There!

I would like to say first and formost, this is not an electric car!
It is a hybrid car! "Hybrid" means a mixture of gas and electric power at the same time.

Once you get past the notion that you are supposed to be able to drive around without gas, you will be fine!

Your observations are normal, and your MPG was quite good for this time of year. A non-hybrid car would have had MPG in the teens in that cold weather.

The car is capable of electric only drive up to 39.9 MPH.
The gas must always come on at 40 MPH and above.
However, this is NOT typical and should NOT be expected.

EV only driving is designed mostly for as you describle, going about in parking lots at 15-20 MPH. The car most often will use electric to 'launch' the vehicle from a dead stop, to 15 or 20 MPH. At a stop, the electric motor has tremendous torque, at the same time, the gas engine has very little.
Once you are rolling over 20 MPH, the electric motor ( all motors ) have very little torque, but that's ok, because at about 20 MPH and over is when the gas engine starts to generate a good deal of torque.

It is like a teter-totter. When one is at the best ( top ) the other is at the worst ( bottom ). Above about 20 MPH the computer calculates the most efficient torque will be from the gas engine, so the gas engine starts.
It is a balance act. It is a "hybrid" car, and you will get electric boost at all speeds, if needed to augment the gas engine.

Think of it this way: The car has a 4 cylinder engine. Those 4 cylinders can do most of the work, most of the time, above 20 MPH. When they get "maxed out" then the electric motor helps at the same time, which is like getting the power of a V6.

The 4 cylinders are very poor at moving the car from a stop.
Engine on ( for heat or A/C ) or not, you will start from a stop with electric power each and every time.

HTH, and I have been an owner for 4 years, and would be happy to answer any specific questions you may have.

-John

 

Also, do you know how large the High Voltage hybrid battery pack is?
It is quite small really. It is 33% larger than one in a Prius, but the pack is still quite small.

It is literally 250 "D" size batteries. Add them up, and they don't weigh much more than the standard 12v car battery under the hood of every traditional vehicle.

Another "shocker" perhaps. Do you know how much "power" you get from those 250 "D" batteries? About 400 watt hours. That's it!

It is truly amazing that you can move a 4000 pound vehicle around parking lots and short ( 1-2 miles ) of road at 20-30 MPH with just 400 watt hours of power.

That's the power used running a hair dryer or microwave oven for 15 minutes!
Or a traditionally lit Christmas Tree for 1 hour.

Still "disappointed"???

 

Thanks for the insights GPSman.

Not actually disappointed, just surprised. In hindsight, I guess I expected to be in EV mode to up until 30 o 40 MPH under all conditions. That's why I rented for a few days, to see how it really works.

> ...and would be happy to answer any specific questions you may have.
How fast (10, 15, 20, 30 MPH?) and how far do you go in your FEH on battery when pulling out from a complete stop from a stop sign or a red light?

As a pedestrian, I thought I observed this behavior closely on streets where I walk frequently. I hear and watch HVs (priuses, camrys, accords, and the odd lexus) pulling away from stops without the ICE's starting up until they are well past the intersection where they stopped/started from, ie. they have gone several hundred feet and are accelerating. Now I'll watch it much closer to see if those initial observations were accurate, ... or was it just wishful thinking.

 

You can go zero to 39.9 MPH from battery power alone, however, this is difficult.

The torque of the electric motor goes down with speed.
Double the speed = half the torque.

Let's approximate 400 ft. pounds of torque at 2 MPH.
That would be 200 ft. pounds at 4 MPH, 100 @ 8, 50 @ 16, and only
25 ft/lbs @ 32 MPH.

Now you see why it is rare to exceed 32 MPH on battery alone.

Also, in EV mode, you have a FIXED gear ratio to the wheels.
So the torque does go down in the way I describe above.
You only have a "constantly variable transmission" or CVT with the engine on.

A fully charged battery will drive about 2 miles at 30 MPH if you are on level ground. You must accelerate slowly, since torque is very low at 30 MPH.

On the other hand, you can tow a horse trailer full of horses up a 10% incline at 5 MPH with battery alone.

Additional Info added 2/3/09:

Actual ScanGauge data from my 2005 FEH:

Taking off in EV from a stop, wheel against a speed bump to provide some resistance, 7 amps of power provided 150 Nm or 110 ft/lbs of torque.
Accelerating from 25 MPH to 30 MPH as fast as possible in EV, 35 amps of power provided 25 Nm or 18 ft/lbs of torque.

Torque definately goes down as motor RPM goes up.
To a certain degree only, you can have a steady torque curve, but the amp draw will go up quickly as RPM goes up.
Very quickly, you will be at Max. Amps.

 

I've read all the specs, what are your actual day-to-day experiences. How fast and how far do you go on battery when pulling out from a dead stop?

 

I drive an '09 FEH but am not a hardcore driver in terms of trying to max out my mileage. I drive normal and reasonable. Over 6000 miles I have averaged around 30 miles per gallon. Not as much as the sticker projections but two months of that driving has been below freezing which has dramatically impacted my mileage. Today the temp is just above freezing and I was at 34.1 on my way to work. During the fall I was frequently driving at greater than 34.

Btw, for what it is worth, 30 miles per gallon was my goal and decision point on purchasing this vehicle. It has far and away exceeded my expectations and, imo, is the best vehicle I have ever purchased. I am in KY where the weather can vary greatly in the winter months. We are just coming out of a bad ice storm and I was doing about 27-28 during the past week of severe weather and driving conditions.

One thing this vehicle has caused me to do is rethink my routes. I now drive to work on a route that takes me about 2 miles further but I am able to maximize my mpg by doing so and get in EV much more and stay in it longer on this route.

I know that I have another month or so of weather that will adversely impact my mileage and then I anticipate pushing back into the mid 30's and higher again.

 

The seasonal variation on our FEH is much higher than the variation of our Saturn Ion, but both do it. The FEH gets us an easy 31-33mpg in the summer and down in the low 20's during the winter. The Saturn gets 30-31mpg in the summer and down to 25mpg in the winter. Cold weather, slush on the road, and winter gas formulation really take their toll.

As for accelerating from a stop, in the summer I easily get through an intersection before the ICE kicks on. My wife, on the other hand, can barely roll a foot before it starts. She isn't a lead foot, but tends to smash and ease back which seems to tell the computer "get the ICE ready just in case". That said, our summer mpg is within 5% of each other so you're not talking about a big difference in actual results.

 

This is not true at all. The torque of an electric motor is not a function of the RPM in any linear fashion. It is primarily a function of the amount of current the motor is drawing, with back EMF becoming an issue at higher RPM's. That's the whole point of an HEV! You do not have significantly less torque at 32 MPH than you do at 2 MPH if you have the voltage available. I have accelerated briskly to 45 MPH on electric alone while my FEH was in warm-up mode and the acceleration was just as good @ 40 MPH as it was at 5 MPH. The limitation on EV speed is due to the NVH requirements for a rapid restart of the ICE by the generator while the traction motor supplies motive torque. Of course the required torque increases with EV speed, but the motors can supply it easily but at the cost of much NVH when re-starting the ICE.

 

Interesting statement. Can you elaborate your specific details on 'get in EV much more and stay in it longer'? Do you cruise through intersections longer on EV because the roads are level?, or there are more intersections to cruise through? At what speed are you seeing the ICE kick in? Thanks.