Is it possible (has anyone done this) to use your MMH/FEH as a city commuting vehicle, staying in EV mode at less than 25mph?

 

If you mean using it purely in EV mode the answer really is no. The battery only will get you a couple of miles, the engine always starts for a short time when you turn the key, and will restart whenever the engine gets cold.

Its not an electric vehicle.... its designed to recapture braking energy and use it for the next acceleration mainly.

 

Thank you for your reply. I realize that it is a hybrid and not an electric vehicle. I was just curious if, through a lot of regen braking in the city, if the MMH/FEH could survive in the jungles of suburbia at less than 25mph.

 

In my experience, the recapture of braking energy is not enough to offset the requirement for constant accelerations of city traffic. At some point, no matter how it's driven, the ICE will need to recharge the HV battery.

I've noticed if you EV from 55%-40% SOC with fake shifting after ICE restarts, my mileage can go from ~20mpg(at first EV event) to ~40mpg (40% SOC).

The mileage penalty for recharge is quite severe - if I nurse at ~25 miles per hour I can limit mileage loss to 31-32mpg to get SOC back to 53-54%.

After repeating this cycle again and again, my urban mileage seems to average about 36 in mid 50's temps. Not bad considering it's brand new and it beats the sticker mileage for a FWD, but I am having a lot of fun learning how to drive this amazing machine.

 

Ah... we get alot of the other question. It will do quite well in suburbia, in fact better than it will with long highway trips. I find most of my trips where I'm going <45mph I can get nearly 34mpg even in the 4WD without any real hypermiler trips other than taking it easy. The engine will come on regularly, but still thats much better than the V6 equivalent. On the freeway for long trips I can drop to 29-30 if I'm going 70.

 

This vehicle excels in suburbia and more rural areas with only the occasional stop. True "city" driving, with congested roads and redlights every block are not ideal for this vehicle. All of the stopping and starting burns through the charge quickly, and there is not enough braking or driving with the engine on to keep the battery charged. You will find in heavy city traffic that you rarely ever get the battery fully charged and will often have the engine on at stops or during mild acceleration as the battery is too low. In the burbs and semi-rural areas, there is more cruising at 45mph which is just about ideal with the engine on, and less stopping and starting. I get 35mpg without trying when I am over in NJ....but driving back and forth across center city Philadelphia my lifetime average is closer to 26 "city". Highway ratings for this vehicle are also understated as I can easily get 33mpg if I keep it under 65mph.

All of that is NOT to say it is not more efficient and more valuable than a traditional vehicle operating in town, it just will not be operating at its peak. Even though you may only get 24-26mpg in heavy traffic....less than EPA....remember that ALL the other cars are also getting much less than their EPA #'s too. PLUS your engine can shut off at most of the red lights...the rest of them are left idling burning $3+/gallon gas and polluting.

 

Thanks! It will be fun learning how to get the max out of my new MMH.
My salesman told me last night that he expects to have a VIN by some time next week. I CAN'T WAIT!!!

 

Thanks Tim! I look forward to getting the max mpg's out of my MMH.
I will need to relearn how to drive!

 

#1 I have gone 8 miles and probably, 13-15 minutes in EV.

Of course, it was all downhill from 8,000 feet to 5800 feet!

#2 I just did a very accurate test ( as accurate as humanly possible )

I went to a farm road ( with little traffic ) and it had rolling hills, but no great elevation changes. ( Minnesota farm lands )

It was 28 degrees, and I was using 30% ethanol. ( In Minnesota they have ethanol coming out of their {corn} ears. ) And ethanol is about $2.10 a gallon now. I drove 5 miles at 55 MPH to get everything "warmed up".

Then, I found a stretch of road with 8 miles between stop signs.
I accelerated ( on gas ) from zero to 35 MPH @ 2400 RPM.
Then I set Cruise Control to 35 MPH and let her go 8 miles.
Then I stopped. Turned around, and accelerated at 2400 RPM and set CC to 35 MPH for the return trip.

Then I did the same 16 mile round trip using as much EV as possible. I would accelerate in EV as best I could, then use some gas to get to 39 MPH, then tap the brake briefly, to evoke EV, then I would use EV to keep a steady 33-35 MPH. There was only 1 stop, and only 1 time I used the brake. So nearly all the EV battery juice came from the generator, not the regen.

Here are the ScanGauge readings:

On Cruise Control:
Battery SOC at start of drive = 53.0%
Average Speed 34 MPH
Distance 16.0 miles
Max. RPM = 2387
Battery SOC at end = 53.0%
MPG = 41.8 ( with 30% ethanol )

Driving manually with large amounts of EV
Battery SOC at start of drive = 53.0%
Average Speed = 33 MPH
Distance 16.0 miles
Max. RPM = 2640
Battery SOC at end = 52.5%
MPG = 44.6 ( with 30% ethanol )

So you can do better than steady criuse control, but it takes practice, and you really need to work at it.

The difference was only 3 MPG since I was doing pretty much steady-state driving. The difference would have been much greater if I was in the city and had to stop every 2-3 blocks. The range in the city would have been more like 35 MPG to 48 MPG.

Hope that helps!
Happy Holidays!
-John

 

Great numbers John. Now if I can only find some Minnesota farmlands here in Rhode Island?
But seriously, those are some great numbers. I hope to put all those hypermiling techniques into effect with my current car as well as my MMH.
I was told to expect a VIN within a week. (fingers crossed!)