288 MPG Best Case is More Than Twice the EPA Range and MPGe

Mitsubishi i-MiEV Forum

Help Support Mitsubishi i-MiEV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

FiddlerJohn

Well-known member
Joined
Jan 7, 2012
Messages
244
Location
Bowie, Maryland
Seeing the details of the EPA test helps me to understand what a great car the i is.
http://www.epa.gov/nvfel/testing/dynamometer.htm

The City test is usually called the LA4 test: 126 MGPe
http://www.epa.gov/nvfel/methods/uddsdds.gif

Highway: 99 MGPe
http://www.epa.gov/nvfel/methods/hwfetdds.gif

That is the EPA test.

Now look at what you can do, if you have to:
http://www.youtube.com/watch?v=zqSLNX3WlHY

* * * Range 137 miles *** . . . * * * 288 MPGe * * *

Wow! 219.5 kilometers on one charge is ~ 288 MPGe ! Wow!

220 kilometers = 137 miles
EPA Gallon=33.7 kWh
iMiEV has 16 kWH or 0.475 of a Gallon
137 miles / 0.475G = 288 MPGe WOW!
 
FiddlerJohn, thanks for posting and I see there are some updates as well. What follows is a modification of a rant I published over a year ago...

The purpose of the EPA Monroney stickers is to give consumers some standardized idea of what it costs to drive a vehicle, considering only energy ("fuel"). To this end the EPA has spent a fortune designing models which attempt to simulate how a 'typical' consumer drives and how a vehicle behaves in those driving conditions.

The EPA, instead of recognizing that electric vehicles are a different animal whose metric is kWHr/100miles or miles/kWHr and simply using these units, decided to attempt 'equivalency' and get back to something everyone is used to: miles per gallon. They implemented this using the energy contained in a gallon of gasoline and converting it to kWHr, specifically, 33.7kWh/gallon. Sorry, but while technically correct, this metric shies away from the fundamental reason for using miles per gallon: COST.

Utilizing the same EPA standard drive cycle for both gasoline and electric vehicles and since cost is the motivation, I contend that there are only three variables which should be considered when comparing "fuel" consumption performance amongst vehicles using disparate energy sources: ENERGY QUANTITY, ENERGY COST, and DISTANCE, measured by gallons or litres from the pump and kilowatt-hours out of an EVSE, $/gallon or $/litre and $/KWHr for that "fuel", and miles or kilometers for distance driven. Although I recognize the various conversions amongst energy units, since the purpose of the EPA sticker is to compare "fuel" consumption COSTS, I contend that $$ paid by the consumer (and not energy content) is the most reasonable common denominator yielding an apples-to-apples comparison.

Upstream or downstream energy costs (be it electricity generation or liquid fuel production) and recovery benefits and all the associated social, political, production, transportation, tax-related, health-related, etc., costs and benefits, although important and worthy of separate discussion, I believe to be irrelevant when discussing out-of-pocket expenses for the "fuel" to drive a vehicle.

For standardization, I accept whatever drive cycle the EPA wants to put out there, recognizing that a hypermiler can very easily beat the current gasoline ratings and that judicious use of regen has a significant effect on extending an EVs range.

The iMiEV EPA sticker says 30KWHrs per hundred miles. I presume that is 30KWHr out of the EVSE (thus taking into account all the vehicle's subsystem's inefficiences), and that regeneration has been optimized. Although I personally think this number is high, for argument's sake, let's accept it.

I had written a bunch of examples to illustrate my point; however, it was easier to simply create a spreadsheet so you can choose your electricity cost and current gas prices to yield the equivalent "miles per gallon".

iMiEVMPG.pdf


Sorry, but whereas I understand how EPA used energy equivalency, I contend that $$ equivalency is the more valid metric as the whole idea is to compare COST. I can understand why they didn't go this way - simply because of the ever-changing cost of both gasoline and electricity.
 
JoeS said:
... I contend that $$ paid by the consumer (and not energy content) is the most reasonable common denominator yielding an apples-to-apples comparison....

http://www.katiekat.net/Vehicles/Mitsi/iMiEVMPG.pdf
...
  • $ / g $3.50 $3.60 $3.70 $3.80 $3.90 $4.00
    $/kWh
    $0.10 116.7 120.0 123.3 126.7 130.0 133.3 ...
    $0.11 106.1 109.1 112.1 115.2 118.2 121.2 ...
    $0.12 097.2 100.0 102.8 105.6 108.3 111.1 ...
    ...
    $0.26 044.9 046.2 047.4 048.7 050.0 051.3 ...
    ...
    $0.33 035.4 036.4 037.4 038.4 039.4 040.4 ...
... Left column denotes electricity cost in $/KWh
Top row denotes gasoline cost in $/gallon
Resulting data represents equivalent Miles Per Gallon
...I contend that $$ equivalency is the more valid metric as the whole idea is to compare COST...
Wow! JoeS mentioned this before, but the chart drives the point home. "Follow the money."
In another post I say for $0.11 for a kWh, and the EPA Gallon of Gas = 33.7 kWh which is a "Gallon of Electricity."

$0.11/kWh x 33.7 kWh = $3.70 for a "Gallon of Electricity"

On the JoeS chart the $0.11/kWh row intersects the $3.70 column at 112 MPG (the EPA MPGe that most of us should beat.)
Now if gas goes up to $4/g, the 112 MPGe iMiEV now gets the a MPG$ equivalent of 121 MPG$ just because the 'i' is using a cheaper fuel.

Alternatively the cost of electricity would have the TRIPLE to $0.33/kWh (keeping gas at $3.70) for the 'i' to break even with a 37.4 MPG gas car.

Energy wise the iMiEV is still 112 MPGe for the entire chart. The JoseS chart allows us to quantify changes in fuel cost using a MPG$ comparison.

The iChart gives Range as a function of Speed and Bars. The JoeS chart gives the equivalent MPG (I call MPG$) allowing us to compare an EV to a gas car at different fuel cost.

Thanks to JoeS for making me think in a new dimension.
 
JoeS said:
... EPA used energy equivalency, I contend that $$ equivalency is the more valid metric...

JoeS is right. The EPA uses an energy equivalency with it's MPGe, but on the top right of the label, the EPA attempts a type of $ equivalency with "You SAVE $9850 in fuel cost in five years compared to the average new vehicle." The EPA $ equivalency uses a fixed $/kWh and MPG to compare to "a standard" car. The MPG$ JoeS chart allows us to vary the $/kWh, $/Gallon and MPG to make cost and MPG comparisons between all cars.

Check out this link the the EPA window Sticker on this iMiEV:
http://www.google.com/imgres?q=epa+...bnh=129&tbnw=186&ndsp=16&ved=0CJgDEK0DMF447QE


This link shows a different new EPA label with "Use Your Gas Prices & Annual Miles" & "Energy Consumption in kWh/100 miles."
http://www.google.com/imgres?q=epa+...nh=111&tbnw=193&ndsp=16&ved=0CLELEK0DMNECOO0B

Here is the new EPA site for MPG$ type comparisons, but I don't understand it:
http://www.fueleconomy.gov/feg/2001customizef.jsp
 
I first published my rant on this forum back in February regarding MPG$ equivalency being the 'proper' way to compare "miles per gallon" between gasoline vehicles and electric vehicles, using $$$ as the common denominator.

http://myimiev.com/forum/viewtopic.php?p=923#p923

Well, based upon my actual consumption, I've updated the spreadsheet. It shows that, for example, with our current gasoline price of $4.20/gal and my off-peak electricity rate of nine cents/kWh (if I were to pay for my electricity), this would yield an effective 198.4mpg for my little iMiEV. :!: Yes, we've found the Silver Bullet for high gas prices (thanks for the concept, psyflyjohn).

iMiEVMPGActual.pdf
 
Hmm, with my high Honolulu electricity costs (~30¢/kWh), even with Honolulu's high gasoline prices (~$4.15/gal. today), this spreadsheet indicates that the fuel for my Honda Insight would cost less than that for the i that I plan to buy :eek: Our condo association buys electricity in bulk for which each resident pays his share, so there's no E.V. rate available.

Fortunately, I don't have to make a choice because our Insight is saving us lots of gasoline money in Sweden where it will stay when we buy the i in Honolulu :D

The point I'm trying to make is that there are some locations where fuel for the most efficient non-EV cars can cost less than that for an i which sort of surprises me.
 
If you were using MPG$, then yes, I suppose maintenance cost should probably be in there, but then so should the cost of gasoline, shouldn't it? How does the driver in Saudi Arabia who pays 30 cents a gallon to fill up his ICE factor in here?

The MPG figure for ICE cars is a way to compare the actual quantity of fuel each car burns, irrespective of price, which is why it's a good measure - We're comparing apples to apples because adding in variable costs in any way upsets the applecart for a meaningful comparison between one car and another so cost cannot be a factor if you want your number to mean anything

When you look at Joe's MPG$ for EV's, the same thing horribly skews your comparisons, making them meaningless. What someone pays shouldn't throw off the number if you intend to use it for a meaningful comparison. Joe pays 6 cents for his energy and gets nearly 200 MPG$ while alohart who drives the same car pays 30 cents for his, so his number is only 1/5th of Joe's for the same miles driven - If those numbers were on the window sticker, Joe's car will be selling like hotcakes, while alohart's car will become a lot lizard after a few months . . . . who wants to buy the car that costs 5X as much to operate than the other one does?

The only way to get a number than means ANYTHING is to get cost completely out of the equation - Joes' car is not really 5 times as 'fuel efficient' as aloharts is . . . . unless you use something like MPG$ to completely throw off the results of your energy comsumption. My ICE is much more 'cost efficient' than the same car someone is driving in California because they are paying $4.20 to fill it up and I'm only paying $3.40

So . . . . if we wanted to make a meaningful comparison of sorts between EV's and ICE powered vehicles, what's the only way this could be done? We would have to peg the energy in a gallon of gasoline to some number of kilowatt hours of electricity irrespective of the cost of either. You may not be happy with the number thay came up with when they did this, but it is the only way you can get an 'apples to apples' comparison where neither the cost of your electricity or the cost of their gasoline can upset the comparison, otherwise you're not comparing anything

Joe wants to use his 6 cents per Kwh to make his EV look better in the comparison because his gas is $4.20 a gallon . . . . and the ICE numbers don't factor that in at all - How does his MPG$ give us any meaningful comparison between his EV and my ICE? It doesn't

MPGe was designed (just like many other things about this car) to give a comparison between driving an EV and driving an ICE powered car, and it does a pretty good job of that, IMO

Don
 
Personally I think the mpge figure has limited value. Basically the EPA set up the formula to compare BTU's. So the MiEV's 112 mpge means a lot less BTU's burned than a car that gets 30 mpg. But the selling point of an EV is reduced pollution and reduced fuel cost and the mpge figure by itself implies significantly reduced cost and reduced pollution which may not be the case depending on where you live. I think the EPA should come up with something like an Energy Star label for EV's.

Energy star labels on appliances give consumers an estimate of yearly energy consumption and yearly operating cost with the operating cost based on a national price average for electricity or natural gas. And the label shows how that appliance's operating cost compares to similar appliances. A similar label for EV's would be a bit more complex because it would have to compare EV's against gas vehicles, but it can be done. The consumer would then have to look at the average gas price and average electricity price used for the label and compare them to local gas and electricity prices.

Unfortunately this excludes pollution considerations. it would be even more difficult to come up with a simple chart that compares the pollution produced by an EV with the pollution produced by similar gas vehicles, especially because how much pollution an EV produces will depend on the type of power plant where you live. But I hate to see the selling point of EV's limited to a cost comparison.
 
Don said:
...The only way to get a number than means ANYTHING is to get cost completely out of the equation...
Hi Don. Whereas we usually agree and complement (and compliment) each other, this topic is one we can roll up our sleeves on... ;)

First off, let's agree that we are only talking about energy ('fuel') and fuel consumption of electric and gasoline vehicles. All other elements, although important when talking about total operating costs, are off the table. Similarly, we're not talking about reduced pollution, health benefits, etc., that may have been significant reasons why we bought our iMiEV in the first place.

Since we're in the US and discussing the Monroney sticker, we'll stick with gallons and mpg and not litres or litres/100km. Happily, kilowatts and kWh are universal.

Next, I am well aware that the EPA took the energy equivalency approach, using 33.7kWh/gallon of gasoline. Within the Monroney sticker is their assumed cost basis for electricity (12 cents/kWh), with gasoline assumed cost being well-hidden but if you work it backwards from 22mpg and 15K miles/year and $12,600 over 5 years that gives us $3.697/gallon.

Allright, with that out of the way, what's the beef?

My contention is that COST is THE reason that "miles per gallon" is being discussed in the first place. The consumer doesn't give a darn about relative efficiencies - the consumer simply wants to know how much it will cost to drive the vehicle, with mpg and fuel cost in terms of cents/mile being reasonable and well-understood metrics.

The consumer looks at the iMiEV Monroney sticker 112mpge and thinks, wow, that's great! The examples alohart and you (Saudi Arabia) pointed out fully support my case. In terms of fuel cost per mile, in Hawaii alohart's efficient gasoline car costs less to drive (fuel cost) than our iMiEV. Thus, I contend, the Monroney sticker utilizing energy equivalence is misleading the consumer - in that locale, the iMiEV fuel cost/mile will be greater than that of an efficient gasoline car.

On the other hand, my table clearly shows the mpg equivalence for a given price of electricity and gasoline which the consumer can directly compare to any gas-guzzling chariot's mpg in the area they live in.

Don't worry, I don't expect to see my chart showing up anywhere soon ... it's primarily of academic interest, anyway, and I suspect most consumers don't know their electricity costs in terms of cents/kWhr.

Thus, Don, we agree to disagree: I believe COST and not energy efficiency is the underlying common denominator in mpg discussions.

BTW, tonymil, my take is that the Monroney sticker is indeed EPA's attempt at an EnergyStar label.

PS Don - I used nine cents/kWh (not six cents/kWh) for my own case - if I paid for my electricity. With my solar panels amortized elsewhere I get infinite mpg$ with my iMiEV. :roll:
 
JoeS said:
My contention is that COST is THE reason that "miles per gallon" is being discussed in the first place. The consumer doesn't give a darn about relative efficiencies - the consumer simply wants to know how much it will cost to drive the vehicle, with mpg and fuel cost in terms of cents/mile being reasonable and well-understood metrics

Don't worry, I don't expect to see my chart showing up anywhere soon ... it's primarily of academic interest, anyway, and I suspect most consumers don't know their electricity costs in terms of cents/kWhr.
I respectfully disagree - I think about all the average consumer really understands is the relative efficiencies

I don't think most consumers know what their actual operating costs are (or would be) anyway, Moroney sticker or not since the cost of gasoline varies so much week to week and state to state . . . . sometimes even hour to hour. About all they really understand is . . . . that it costs exactly half as much to drive a 40 mpg car as it does a 20 mpg car, so 40 is better than 20. President Clinton drove this point home Wednesday when he said that no matter what gasoline costs you, it's going to cost you half as much when you have one of the new 54.5 mpg cars in 2024

For most of us, that's all we understand

True, most don't know what they pay for a Kwh of electricity, but I'll bet most also don't have a clue what they paid for a gallon of gas averaged over the past year either. If you ask most any average driver what they paid in total for gasoline last year, I think you'll get lots of shrugged shoulders and very few could come up with a number within a couple hundred of the correct one. This is not something very many of us know. If my daughter had any clue, she'd make sure the kids were ready when the bus comes so she doesn't have to drive them to school

I truly believe that the mpg number alone means more to them than any other bit of information on the Moroney sticker . . . . and 112 mpg translates very well in the average brain which knows that 45 mpg is a really good number - Trying to get any more technical than that means that very few in your audience will get anything out of the discussion and trying to compare actual costs for them personally is a very complicated lost cause

When a stranger asks me about the car, invariably the first question is . . . . "What sort of mileage does it get?" - THAT'S how they compare one car with another. When I tell them it uses no gas and costs about 3 cents a mile to drive, I usually get blank stares . . . . I think because they have no idea how that compares to what they're driving. Before I bought this car, I had no idea how many cents per mile my ICE cost to drive - When the tank was empty, I filled it up, grateful that the tank was small and I could go 400 miles before I needed to do it again

It's almost impossible to talk dollars when you're discussing one car - Varied cost of gasoline, varied mileage depending how and where you drive, whether the car is well maintaned or not, summer or winter formula fuel, etc, etc. Now try to compare costs with a totally different kind of car which doesn't use gasoline at all and where the 'fuel' costs vary even more widely than the cost of gasoline does and all you're going to come up with is a million numbers which quickly beome meaningless for most of us

I understand that opinions will vary and I respect the fact that mine is no more valuable than anyone elses ;)

Don
 
Here in New Zealand, Fuel is pretty expensive. Got invited to a party about 50 km away, as did my friend, we had to travel in seperate cars due to him being on call for his job, and I needed to be home earlier than him also.

He was discussing how expensive it was to travel there and back, particularly if he had to come back early to a call out and then back to the party to pick up his family.

I mentioned it would be only $ 3 NZ in the imiev, to which he said yes, but that would mean would not have enough power to go back to the party. I said he could swap to the petrol car if he had to go to work.

While at the party, even though I was there in the Hilux, I got talking to one of the guests about the imiev, and she was really impressed about the $ 3 refuel of the car, and the range for running the kids about to sports.

I may drop off a flyer to her about the car. While there, I spoke to a local councilor about power points for the local sports' grounds so people could refuel the imiev. He said he would put me in touch with the sports ground guy.

I have a client here in NZ on holiday from Aussie, and he can't get over how expensive it is to refuel the petrol Adventra here in NZ. He said it was about 80 $ Aus, compared to 140 $ NZ !.
To go the same distance in the imiev, it would be about 12 $ NZ.... :D :D :D
 
Thought I'd revive this old thread - borrowing from the TOU thread -
Mart said:
... please realize the MPGe is solely based on energy content, not price. It may be confusing to people to use it in a financial context, even though that's what most people are really wanting to know, "How much money do you save?". Unfortunately, people are used to MPG figures on the window, and by establishing MPGe the government has gotten itself into the same quagmire of measuring light bulbs and lamps in "incandescent watt equivalent" rather than using the more effective lumens and CRI. Edmunds argues for a move to Monthly Fuel Costs, but even this must be based on an "average" driver figure which varies as much as EPA MPG estimates. http://www.edmunds.com/car-news/fuel-mileage-equivalency.html

It's hard to come up with a money per mile estimate with fluctuating fuel prices, differing rates, and currency value fluctuations occurring daily or hourly. This editorial and the comments might be worth a read. http://insideevs.com/op-ed-time-new-metric/
Mart, thank you very much for this link. The comments section in that insideevs link I found very entertaining - it's been some time since I've seen so much lively banter about metrics - an interesting read if you're into that stuff.

The traditional metric for efficiency that the EV crowd used for many decades (a century?) was Wh/mile or Wh/km or kWh/100km (I won't get into a debate as to whether there should be a multiplication dot between the "W" and "h") - suffice it to say that distance is in the denominator and energy is in the numerator. Thus, the lower a vehicle's energy consumption/unit distance, the lower the number. When it comes to conventional ICE fuel consumption, the US is alone in using the back-asswards Miles Per Gallon (MPG) metric, whereas the rest of the world uses the far more logical litres/100km metric. Unfortunately, auto manufacturers have (and, I confess, so have I) been continuing this sin (?) and using the metric of miles/kWh; for example, the Leaf has this number displayed on their dash, although it further confuses the issue as it represents battery-to-wheels and not wall-to-wheels. Perhaps this distance/energy metric is in keeping with our national 'bigger is better' obsession?

Anyway, after all the give-and-take in the comments section of that article, there seemed to be no consensus on how to change EPA's current MPGe metric - even though that metric was vilified by most and the Joule over distance was felt to be the 'purest' metric.

In the end, it doesn't matter, as we all know that Your Mileage May Vary dramatically, depending on how you yourself drive your i-MiEV!
 
I think for the common man or woman on the street, the best you can tell them is the EPA estimate of 112 MPGe. After reminding them that it uses electricity instead of gasoline, they'll want to know the price of a "gallon" of electricity. :roll:
 
Mart said:
I think for the common man or woman on the street, the best you can tell them is the EPA estimate of 112 MPGe. After reminding them that it uses electricity instead of gasoline, they'll want to know the price of a "gallon" of electricity. :roll:
The EPA considers 33.7 kWh equivalent to 1 gallon of gasoline, so 1 gallon of electricity would cost 33.7 divided by the cost of a kWh of electricity. In Honolulu, electricity costs ~30¢/kWh, so 1 gallon of electricity would cost ~$10 here.
 
Back
Top