Gas MPG

[Rhyalus]

Has anyone experimented with running a couple of tanks of gas in hybrid mode only?  (short runs or even a day or two is probably not a good measure of actual MPG)

 

I am thinking of resetting one of the Trip counters and seeing what it says I am really getting.

 

Thanks,

R

 

[howardbc]

I would really like to know what the true MPG is for the car when in hybrid mode. I suspect it isn't very good. I've seen readings in just the 20s when the battery is depleted and when I've been in just hybrid mode since the last time I turned the car on. 

 

But maybe it's better than that. I remember that the MPG for my Prius was pretty bad when I first filled up with gas; then it would go up into the 40s after a while. 

 

I would never expect the Fusion Energi to get MPG anything like the Prius, but a true MPG for hybrid even in the high 20s would be okay. Anyhow, I for one would love to know what the actual MPG is for the car when it's running only in hybrid mode. Thanks. 

[jeff_h]

I would never expect the Fusion Energi to get MPG anything like the Prius, but a true MPG for hybrid even in the high 20s would be okay. Anyhow, I for one would love to know what the actual MPG is for the car when it's running only in hybrid mode. Thanks. 

 

Last weekend we took a ride that was 40 miles down the road, were leaving at 5PM when it was still 90 degrees, knew we were coming back late at night around 11PM or so... so I figured I would use 'EV later' as running EV with the AC uses up the HVB more quickly... and then open the windows and moonroof and go without AC coming home when it was cooler and getting the most out of the EV. 

 

Anyway -

 

40 miles down and stop to pick up friend - 46.9 MPG (this was on I-95, cruise set on 70, hybrid only)

5 miles from picking up friend to destination - 51.1 MPG, hybrid only (but was on rural roads with speed limit of 45 and slight rolling hills and little traffic, which normally makes for good MPG)

 

40 miles back at 11pm with using the saved EV - 60.9 MPG for the trip  (combined EV and hybrid)

 

I was pretty happy with the results.

Edited June 25, 2013 at 11:57 PM by jeff_h

[lokicat]

At 70 MPH and no climate controls going I get 47 MPG. Same speed with AC going I get 41 MPG.

 

One thing I would recommend is to not use hybrid mode for short distances of less than 5 miles. Like most cars, your engine needs a higher amount of gas to get to stable operations so the first 2-3 miles will be under 20 MPG. Same thing on my Prius.

[howardbc]

Wow, these figures are very encouraging! Thank you so much to everyone for letting us know your experiences.

 

So if I understand correctly ... for long road trips I should not select any of the EV modes if I won't be able to recharge the battery on a regular basis. 

 

Thanks again.

[BadRock]

Here are a few of my longer drives....

 

[larryh]

You could probably get even better mileage with higher driving scores.  You should be able to get them up in the 80s.

Edited June 26, 2013 at 10:24 AM by larryh

[Russael]

Hahaha... BadRock is rated a D- for driving. :) (I'm just razzing you)

 

On another interesting note... on the trip with the 57 driving score... it says you used .2kWh, but also says 53% was EV.  Did you start that trip in hybrid mode?  If so, maybe that EV bar counts hybrid operation since you technically do run on and off in an EV mode.  But if that's the case, the other 2 trips should've been rated similarly, especially since you started with a much fuller battery, but for those, it claims you had even fewer EV miles.  I wonder if reporting is still messed up or something... or maybe that bottom trip was surface travel while the other two were highway?  Dunno... some of that isn't making sense.

Edited June 26, 2013 at 11:55 AM by Russael

[BadRock]

You could probably get even better mileage with higher driving scores.  You should be able to get them up in the 80s.

Indeed, it really bangs you for "cruising" at higher speeds. Most of these longer trips I was driving at 80+ MPH.

 

Hahaha... BadRock is rated a D- for driving. :) (I'm just razzing you)

 

On another interesting note... on the trip with the 57 driving score... it says you used .2kWh, but also says 53% was EV.  Did you start that trip in hybrid mode?  If so, maybe that EV bar counts hybrid operation since you technically do run on and off in an EV mode.  But if that's the case, the other 2 trips should've been rated similarly, especially since you started with a much fuller battery, but for those, it claims you had even fewer EV miles.  I wonder if reporting is still messed up or something... or maybe that bottom trip was surface travel while the other two were highway?  Dunno... some of that isn't making sense.

D has always stood for dandy in my books!  :rockon: 

 

Any of the trips that show a XX.X kWh reflects some actual EV driving meaning that the HV battery had some charge at the start of the trip OR the regen was great enough to provide a significant charge to the HV battery and then use the energy.

 

In the case of my 189 miles trip with 4.7 kWh of usage the car had zero charge at the time of departure however I was driving over mountain passes and managed to regen a ton of energy. That is how I managed to use so much juice. 

 

When you try to estimate gas only in this car it's impossible because there is always an electric factor to driving, the more hills and/or stops, the more regen.

[larryh]

For the 189 mile trip, you have achieved higher MPG than what is stated--probably more like 44 MPG.  You ended up with a lot more charge in the battery than when you started.  You could now go another 15 miles or so without using gas (but not if you go 80 mph).  I suspect that if you had changed the display to show MPGe rather than MPG you would see the higher mileage (assuming it can take negative consumption into account, i.e. more charge in the battery at the end of the trip than when you started).  In hybrid mode, MPGe and MPG would show the same mileage provided the charge in the battery at the start and end of the trip was the same. 

 

Of course, if you exceed 85 mph, the electric engine can't power the car.  I assume that the car will then simply continue to charge the battery until you slow down.  Going over 85 mph for some distance may be another way to charge the battery (and to end up with a large fine for speeding at least here in MN  :doh: ).

Edited June 27, 2013 at 09:24 PM by larryh

[Rhyalus]

Just as an FYI, I stopped plugging in my Energi a couple of days ago.  I am going to run a tank of gas to get a better idea of the efficiency of the car without wall power...

 

Hard to do...  :-)

 

R

[larryh]

I reset Trip 1 the previous time I filled the tank with gas.  When I filled up the tank this time, it took 11.2 gallons until the pump shut off.  Trip 1 claimed I used 11.35 gallons.  So I added a little more gas to get 11.35 gallons.  The trip odometers seem to accurately compute MPG and gas consumed.

[howardbc]

You guys are "pioneers," but I will appreciate any info on what MPG you get without plugging in. 

 

Thanks. 

[Rhyalus]

So can someone help me figure out what this means?  I did not think to check my odometer overall before beginning the test:

 

 

40.3 * 4.65 = 187.395 which mostly makes sense.  Does the 84.4 EV mean that I traveled an additional 84.4 miles for a total of 272.1?

 

(Note:  This was a mix of local and highway driving, with a lot of AC, normal (but controlled) acceleration and use of EV when possible (monitoring the "Empower" gauge).

 

Thanks,

R

 

 

[murphy]

Was your HVB empty before this trip started?  I think that is what the 0.0kWh means.

If is was then you had 84.4 miles attributable to electric operation but all miles are attributable to gasoline.

The hybrid battery was charged by the ICE burning gasoline.

[Rhyalus]

Yes - the purpose of this experiment was to see gas MPG.  So are we saying that my TOTAL mileage was 187.7 miles - subtract 84.4 EV miles (equals 103.3), and then divide by total gallons used (equals 22.22 MPG)?

 

If so, the CAR got 40.3 MPG of gas used, but the ICE engine operated at 22.2 MPG?

 

R

[larryh]

You only traveled 187.7 miles.  Of those miles, 84.4 were with the ICE off.

[larryh]

The ICE charged the battery.  So it consumed fuel to charge the battery.  The EV miles resulted when this energy was reclaimed from the battery.  Your actual MPG is 40.3 as shown.  No plug-in energy from the wall was used to power the car. 

 

Actually, it would be better to display MPGe.  That would take into account any difference between the battery charge level before and after the trip.  That would guarantee that you did not use any energy generated during the previous trip and you do not have an residual energy generated during this trip that you didn't use.  But the difference should be minimal for this many miles.

 

You have almost 7 hours for the trip, but only 187 miles.   The average speed is 27.7 mph.   Were you doing a lot of city driving?

Edited July 5, 2013 at 08:37 PM by larryh

[Rhyalus]

Hmmmmm, the ICE worked harder to charge the battery?  I am not sure I agree.  Most of the EV miles were probably generated by the braking, though I do see some regen when coasting.  Even this is not always true because coasting sometimes changes over to EV operation which can use power rather than regenerate it.

 

The Chevy volt uses gas to charge the battery - this is a more direct relationship than what we have on the Energi.

 

I wonder why the 2.0L 4 cyl engine is not more efficient?

 

My conclusions:  1) The 43 MPG rating is probably correct.  Under mildly different conditions (no AC, etc.) I could have gotten 43.  2) The ICE is horribly inefficient compared to today's available technologies.  On the other hand, the technology of turning on and off so the EV drive can take over is what allows the better use of fuel.

 

I may terminate the experiment because I don't think there is anything else to learn.

 

R

[Rhyalus]

BTW, I think MPGe is also a useless rating for end users.  The real rating we should use is $ per mile or miles per $.  Either way this will vary considerably for each person.

 

Of course this is arguable as well, as some people may be more concerned about the use of fossil fuels vs. electric power (hopefully generated in a clean way).  :-)

 

R

[larryh]

Yes, the ICE did have to work harder, at times, to charge the battery in addition to propelling the car.  And yes, some of the kinetic energy of the car was skimmed off and stored in the battery during coasting (the ICE is going to have to provide the power to bring the car back up to speed and restore the kinetic energy that was skimmed off) .  And yes, when stopping, regenerative braking captured much of the kinetic energy from the moving car and stored it in the battery, rather than wasting it as heat energy which occurs with normal friction brakes.  But it was the ICE that provided the power to get the car moving and keep it moving, and hence supplied the kinetic energy that is being captured by the battery.  These are the principles that give a hybrid much better mileage.  It doesn't waste as much energy as a normal gasoline powered engine.  It captures the energy that would otherwise be wasted and stores it in the battery for later use.  There is no way to know what the ICE would get if there were no battery.  In any case, it was optimized to work in conjunction with a battery and probably give poor results without one.  If you coupled a normal gasoline engine with a battery, you would probably get much worse results than the Energi.

 

The purpose of MPGe is to measure energy efficiency.  From the EPA ratings of 100 MPGe and 43 MPG, that informs you using electricity is 2.3 times more efficient that burning gas.   Much of the energy burning gas is wasted.  Only about 1/3 of the energy released from the combustion of gas is actually used to propel the vehicle.  Electricity is 72% efficient, 72% of the electrical energy put into the car is used to propel the vehicle.  So MPGe gives you the overall energy efficiency of operating the car.  How much of the available energy you supplied to the car was actually used to propel the vehicle.

 

Note the energy expended extracting, refining, and delivering the gas to the gas station is not included in the EPA MPGe estimates.  Similarly, the energy required to generate and transport electricity to the wall outlet is not included.

 

If you are interested in the operating cost for the vehicle, the window sticker also provides the estimated annual costs to fuel the vehicle with electricity and gas.

 

I don't think the Chevy Volt is all that different from the Energi.  It also uses regenerative braking to get its EPA rating.  You would have to actually compare the mileage of the Volt after the battery has depleted with that of the Energi to claim one is more efficient than the other.  The EPA claims that the Energi is more efficient.

Edited July 7, 2013 at 12:15 PM by larryh

[Energized]

Hmmmmm, the ICE worked harder to charge the battery?  I am not sure I agree.  Most of the EV miles were probably generated by the braking, though I do see some regen when coasting.  Even this is not always true because coasting sometimes changes over to EV operation which can use power rather than regenerate it.

 

The Chevy volt uses gas to charge the battery - this is a more direct relationship than what we have on the Energi.

 

I wonder why the 2.0L 4 cyl engine is not more efficient?

 

My conclusions:  1) The 43 MPG rating is probably correct.  Under mildly different conditions (no AC, etc.) I could have gotten 43.  2) The ICE is horribly inefficient compared to today's available technologies.  On the other hand, the technology of turning on and off so the EV drive can take over is what allows the better use of fuel.

 

I may terminate the experiment because I don't think there is anything else to learn.

 

R

 

Yes, while in hybrid mode, the ICE charges the small battery at the same time it's powering the vehicle.  You can watch it on the power flow pictorial on the touchscreen. 

 

Under high load conditions, the vehicle draws from both the battery and the engine.

 

 

Here is an example of 100% EV later, Hybrid mode.

 

The EV miles shown came from the ICE.

 

The Regen miles are a small amount of this trip because it was more highway than city.

 

 

 

The bottom line is it took 1.08 gallon to go 50.4 miles.

 

If you only counted the miles traveled while the ICE was on, you might  conclude (incorrectly) that the ICE is inefficient and only getting MPGs in the 20s.

 

That's not how the car works.  While the ICE is on, it's storing EV miles to use when the ICE is off. 

 

For this trip, the ICE was basically only running for half the trip.

Edited July 5, 2013 at 11:00 PM by Energized

[larryh]

Updated my previous post with the following:

 

The purpose of MPGe is to measure energy efficiency.  From the EPA ratings of 100 MPGe and 43 MPG, that informs you using electricity is 2.3 times more efficient that burning gas.   Much of the energy burning gas is wasted.  Only about 1/3 of the energy released from the combustion of gas is actually used to propel the vehicle.  Electricity is 72% efficient, 72% of the electrical energy put into the car is used to propel the vehicle.  So MPGe gives you the overall energy efficiency of operating the car.  How much of the available energy you supplied to the car was actually used to propel the vehicle.

 

Note the energy expended extracting, refining, and delivering the gas to the gas station is not included in the EPA MPGe estimates.  Similarly, the energy required to generate and transport electricity to your wall outlet is not included.

 

If you are interested in the operating cost for the vehicle, the window sticker also provides the estimated annual costs to fuel the vehicle with electricity and gas.

Edited July 7, 2013 at 12:15 PM by larryh

[howardbc]

I still have my data set for MPG but am wondering if I should change it to MPGe, as I am interested in knowing what my efficiency rating is. 

 

I created a spreadsheet and input my EV miles and my regen miles. It shows that I am using EV and regen for around 85% of the miles driven. So if I change the setting to MPGe, would it automatically compute the percentage for mileage efficiency? 

[larryh]

If the console setting is set for MPG, the car will display total miles driven divided by gallons of gasoline consumed by the ICE for those miles (or 999 if no gas was consumed and the ICE did not run).  This isn't very useful to display how efficient the car runs in EV mode.

 

If the console set is set for MPGe, the car will display total miles divided by equivalent gallons of gasoline consumed, which includes the energy consumed by the electric motor and the ICE.  This shows the overall energy efficiency of the car for both the ICE and the electric motor combined.

 

When running in hybrid mode after the battery has depleted, MPGe and MPG settings should display the same value (provided the level of the hybrid battery did not change from the beginning to the end of the trip(s)).

 

I have my console set to display MPGe.  I usually drive in EV mode.  So MPG isn't very useful for my trips.  You can always recover MPG from MPGe, or MPGe from MPG if you keep track of the distance traveled and the kWh of plug-in energy used by the car (shown by MyFord Mobil).

 

If you want to measure the energy efficiency of the car, I recommend using MPGe.  The Energi is much more efficient using electrical energy than using gasoline.  If you display MPG, you are missing the energy that the Energi uses most efficiently from the mileage computation.  I have measured the actual MPGe for the Energi going 70 mph using gas vs. using plug-in electric energy for two different trips.  For gasoline, I achieved 41 MPGe.  For plug-in energy, I achieved 75 MPGe.   The Energy uses plug-in energy approximately 1.8 times more efficiently than energy from the combustion of gas at 70 mph. 

 

MPGe is the only useful metric that we have readily available to make a fair comparison between the Energi fuel efficiency and the fuel efficiency of normal gasoline powered cars.  Comparing the MPG of the Energi with the MPG for gasoline powered car is a very unfair comparison, like comparing apples to oranges.  But unfortunately, the Energi seems to exaggerate MPGe, sometimes by up to a factor of 1.4 times the correct value (the actual factor depends on the amount of gasoline consumed and the charger used among other things). 

Edited July 7, 2013 at 10:40 PM by larryh