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Discussion Starter · #1 ·
I was looking at the display options for energy consumption and I do not see MPGe as an option anywhere. This would make most sense, at least for folks moving over from ICE to EV. Has anybody seen any method of configuring custom display units in the energy consumption section?
 

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MPGe, to my understanding, is not a unit to measure consumption. That’s a calculation done mostly by EPA based on if your car was an ICE car how many miles you could go with the same dollars you spend on electricity, on gas.
So it depends on price of gas, which varies by location/state/country.
 

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Discussion Starter · #3 ·
I do not think so.

Miles per gallon gasoline equivalent is a way of measuring the energy needed equivalent to a gallon of gasoline to travel a distance in miles. Because electric vehicles do not consume gasoline (obviously), the EPA set an equivalent amount of energy in kilowatt-hours that is equal to one gallon of gasoline. According to the EPA, one gallon of gasoline is equal to 33.705 kilowatt-hours. so the math here would be simple enough - MPGe = mi/kWh × 33.705
 

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The unfortunate thing is that the 'real price' of fueling a BEV is hugely dependent upon your electric rates, which vary considerably around the country. So to me the MPGe is only mildly interesting and somewhat useful in comparing BEV A to BEV B. Truth be told, my wife's hybrid Lexus costs less to operate than my I-Pace.
 

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I do not think so.

Miles per gallon gasoline equivalent is a way of measuring the energy needed equivalent to a gallon of gasoline to travel a distance in miles. Because electric vehicles do not consume gasoline (obviously), the EPA set an equivalent amount of energy in kilowatt-hours that is equal to one gallon of gasoline. According to the EPA, one gallon of gasoline is equal to 33.705 kilowatt-hours. so the math here would be simple enough - MPGe = mi/kWh × 33.705
You’re right.
I did a quick research and came across the same article you’re referring to.


I believe this method is flawed though. For example they’re talking about heat generated from gas and electricity, but heat is irrelevant in this case, because the ultimate goal is force.
 

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Discussion Starter · #6 ·
Fair but MPGe is a reasonably well accepted EPA measure for all EVs. It would only make sense to support display of the same metric. The whole mi/kWh is less readable to me, honestly. Perhaps it is just a matter of getting used to it over time, nothing more.
 

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Is the calculation not just

(ppg / ppkWh) x Miles per kWh

ppg is price per gallon

ppkWh is price per kWh.

So my electric bill says I pay 11p per kWh.
diesel at moment is £1.21 a litre which is about £5.50 a gallon.

so at 2miles per kWh that’s 5.5/.11 x 2 so 100 mpge.
 
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Discussion Starter · #8 ·
I do not care about the price aspect of MPGe, since when I run ICE car, the MPG displayed does not include (or care for) the price of a gallon of gas. I am just interested in energy equivalent, not dollar / pound / <put your currency here> cost equivalent.
 

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You can of course always do the math yourself with the formula you provided. If you look online, there is a bit of discussion about energy density of a gallon of gas. It is not always as fixed as there are different factors at play, such as temperature. So as a measure to be displayed in an EV it is probably not all that useful. That is why I am not aware of any EV using it despite the fact that the EPA provides it. I always use the kWh/miles on the dash as that has a finer granularity and also can go negative when regen is active.
 

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mmmzon wrote: " I do not care about the price aspect of MPGe, since when I run ICE car, the MPG displayed does not include (or care for) the price of a gallon of gas. I am just interested in energy equivalent, not dollar / pound / <put your currency here> cost equivalent."
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Wouldn't that conversion just assume some constant multiplier applied to the Mi/kWh? You could change your efficiency display to Mi/kWh" (that is an option!), put a little piece of masking tape on the Cockpit Display where "Mi/kWh" shows up, use a Sharpie and write "MPGe" on it, and pretend! Seriously, though, when driving an ICE I was NEVER concerned on a moment-by-moment basis with exactly what kind of MPG I was getting in the car. I was perfectly happy knowing I got about "abc MPG" and was done with it. "Range Anxiety" has made us EV drivers obsess over what the efficiency is of the car every second----1.4 kWh/mi, BOOO! 2.7 kWh/mi--Top of the World (if you are in an Etron)! That metric seems a little backward looking. The world should be jumping off the "gallon" bandwagon!
 

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You can of course always do the math yourself with the formula you provided. If you look online, there is a bit of discussion about energy density of a gallon of gas. It is not always as fixed as there are different factors at play, such as temperature. So as a measure to be displayed in an EV it is probably not all that useful. That is why I am not aware of any EV using it despite the fact that the EPA provides it. I always use the kWh/miles on the dash as that has a finer granularity and also can go negative when regen is active.
LOL. When I first started looking into getting an EV, I kept running across efficiency estimates expressed as kWh/mi, which is fine, but not how my brain works. I like the number to go up as things get better, and so I went with the inverse. However, recently, more and more I am thinking I should just remove it all together. It's as addictive as checking my cell phone for messages and notifications! I'm thinking I could delete it and be perfectly happy....even happier...not knowing--and much more like driving an ICE!
 

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LOL. When I first started looking into getting an EV, I kept running across efficiency estimates expressed as kWh/mi, which is fine, but not how my brain works. I like the number to go up as things get better, and so I went with the inverse. However, recently, more and more I am thinking I should just remove it all together. It's as addictive as checking my cell phone for messages and notifications! I'm thinking I could delete it and be perfectly happy....even happier...not knowing--and much more like driving an ICE!
The issue with miles per kWh or gallons is that it is a highly non-linear scale and thus does not let you compare between different ranges. A 2 mpg improvement for a car that gets 10 mpg usually is a big increase whereas the same improvement for a Prius is fairly minimal. So I am not a big fan to begin with. But I grew up in Europe so I am used to the liters per 100 km. So kWh per miles is just the EV counterpart to that.
 

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The issue with miles per kWh or gallons is that it is a highly non-linear scale and thus does not let you compare between different ranges. A 2 mpg improvement for a car that gets 10 mpg usually is a big increase whereas the same improvement for a Prius is fairly minimal. So I am not a big fan to begin with. But I grew up in Europe so I am used to the liters per 100 km. So kWh per miles is just the EV counterpart to that.
Right, a lot has to do with what you are used to from the ICE world. I don't really look at the mi/kWh (or inverse) in terms of how much the range will be affected. I look at it more as being a running estimate of how close I am to maximum efficiency for my car. I leave it to the GOM to estimate possible range, but mostly rely on the "% charge" bar for determining if I want to charge my car. I suppose the one exception would be dealing with cold weather. Seeing where my efficiency tops out when it's a really cold day can change my mindset. The significantly higher sensitivity of EV's to cold weather, compared with ICE, was a bit of a revelation to me. I think the EPA should provide both "standard temp" and "cold temp" mileage estimates for EV's. Plus, that might be one area where EV's could differentiate themselves.
 
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