Range from the window sticker

[Maquis]

Sorry, I didn’t intend to get everyone’s fur flying.
I thought if I simply pointed out that generally electricity costs more that gasoline on an energy-equivalent basis, people would simply see it as a “fun fact.”
I‘ll close by attempting to return this thread back towards the original topic, window sticker efficiency.
MPGe is calculated by simply converting M/Kwhr to MPG using the energy equivalence between electricity and gasoline. There are no assumptions regarding ICE MPG, the price of electricity, or the price of gasoline. It’s all science, no economics.

Cheers.

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[Rt1AWD]

Sorry, I didn’t intend to get everyone’s fur flying.
I thought if I simply pointed out that generally electricity costs more that gasoline on an energy-equivalent basis, people would simply see it as a “fun fact.”
I‘ll close by attempting to return this thread back towards the original topic, window sticker efficiency.
MPGe is calculated by simply converting M/Kwhr to MPG using the energy equivalence between electricity and gasoline. There are no assumptions regarding ICE MPG, the price of electricity, or the price of gasoline. It’s all science, no economics.

Cheers.

It is a fun fact indeed. I didn't know that. Anyway I never look at MPG of EVs. In my opinion the MPG of electric cars is the most useless vehicle characteristic ever

 

[Maquis]

It is a fun fact indeed. I didn't know that. Anyway I never look at MPG of EVs. In my opinion the MPG of electric cars is the most useless vehicle characteristic ever

Agreed - but people who are used to thinking in ICE terms needed something to relate to.

 

[generaltso]

It is a fun fact indeed. I didn't know that. Anyway I never look at MPG of EVs. In my opinion the MPG of electric cars is the most useless vehicle characteristic ever

MPGe isn't completely useless. It gives a quick way of comparing the effeciency between electric cars. An EV with a rating of 94 MPGe is generally more efficient than an EV with a 74 MPGe rating.

 

[Rt1AWD]

MPGe isn't completely useless. It gives a quick way of comparing the effeciency between electric cars. An EV with a rating of 94 MPGe is generally more efficient than an EV with a 74 MPGe rating.

kWhrs/100miles is good enough for that. However personally I would prefer to have it as miles/kwHr

 

[Maquis]

kWhrs/100miles is good enough for that. However personally I would prefer to have it as miles/kwHr

That’s common in Europe, liters per 100KM for petroleum (kwhr per 100KM for an EV).

 

[generaltso]

kWhrs/100miles is good enough for that. However personally I would prefer to have it as miles/kwHr

MPGe works better if you're also throwing PHEVs into the mix.

 

[Rt1AWD]

That’s common in Europe, liters per 100KM for petroleum (kwhr per 100KM for an EV).

So for consistency we should probably replace MPG with Galons/100miles as well

 

[Chuck]

I don't agree. 2.9 miles per 45 cents/kwHr is 29 miles per $4.5, which is approximately the same as on gasoline

If you think you'd ever get 29 miles on a gallon of gas for a Mustang or an SUV you're dreaming.

Aside: I live in SoCal but pay only 7 cents per kwh after 10pm.

 

[Mach1E]

kWhrs/100miles is good enough for that. However personally I would prefer to have it as miles/kwHr

Is KwHrs/miles mixing the metric system with imperial?

Shouldn’t we be using Calories instead?

Would be super fun to determine how many calories my car was burning. 1kwh = 860,420 calories.

 

[Rt1AWD]

If you think you'd ever get 29 miles on a gallon of gas for a Mustang or an SUV you're dreaming.

Aside: I live in SoCal but pay only 7 cents per kwh after 10pm.

Unfortunately LADWP customers don't have that option

 

[timbop]

Soo what you’re saying is that I could theoretically fully charge my standard range battery with just two gallons of gas! Lol (before you go on about conversion losses…it was a joke)

Actually that is exactly what the EPA does to compute "Miles per gallon equivalent", or MPGe. The correct value is 33.7 kwh worth of energy in a gallon of gas. Since they round off the kwh/100 mi to a whole number in the report the calculation isn't exact (99MPGe vs 100MPGe for the RWD):

SR AWD:
100 mi / 36kwh = 2.77 mi/kwh
2.77 mi/kwh x 33.7 kwh/gal = 93.35 mi/gal equivalent

SR RWD:
100 mi / 34 kwh = 2.94 mi/kwh
2.94 mi/kwh x 33.7 = 99.11 mi/gal equivalent

SR RWD (assuming the actual kwh/100mi is 33.7)
100 mi / 33.7 kwh = 2.97
2.97 mi/kwh x 33.7 = 100 mi/gal

 

[timbop]

Actually that is exactly what the EPA does to compute "Miles per gallon equivalent", or MPGe. The correct value is 33.7 kwh worth of energy in a gallon of gas. Since they round off the kwh/100 mi to a whole number in the report the calculation isn't exact (99MPGe vs 100MPGe for the RWD):

SR AWD:
100 mi / 36kwh = 2.77 mi/kwh
2.77 mi/kwh x 33.7 kwh/gal = 93.35 mi/gal equivalent

SR RWD:
100 mi / 34 kwh = 2.94 mi/kwh
2.94 mi/kwh x 33.7 = 99.11 mi/gal equivalent

SR RWD (assuming the actual kwh/100mi is 33.7)
100 mi / 33.7 kwh = 2.97
2.97 mi/kwh x 33.7 = 100 mi/gal

You can also use the MPGe to reverse the calculation to see what the achieved mi/kwh is for city and highway, but of course all these numbers include a roughly 10% overhead/loss. Thus the mi/kwh the car reports will be about 10% higher during the tests because the car computes the mi/kwh based on the energy coming out of the battery, which does not include the roughly 10% extra energy that was lost during charging. You also have to remember that the testing is done inside on a dynamometer with fudge factors for things like aerodynamic drag and weather, and the speeds/acceleration/braking follow a simulated drive which may or may not match anyone's actual driving habits. This should give you an appreciation that the efficiency, range, and MPGe reported are estimates of what you will see in the "real world". The same disclaimer goes for the MPG (and thus range) of ICE vehicles, but for some reason lots of people look at the EPA estimated range rating of the Mach E as some kind of "promise" . In actual practice my Mach E typically beats the EPA rating in warm weather but falls short in cold weather. My previous Mustangs never beat their EPA MPG rating and also lost range in cold weather, which is typical of most ICE cars not driven by a hypermiler.

SR AWD:
100 MPGe / 33.7 = 2.97 mi/kwh "city" driving
2.97 mi/kwh x 1.1 = 3.3 mi/kwh from the battery to the wheels (ie what the car reports)
86 MPGe / 33.7 = 2.55 mi/kwh "highway" driving
2.55 mi/kwh x 1.1 = 2.8 mi/kwh from the battery to the wheels (ie what the car reports)

SR RWD:
105 MPGe / 33.7 = 3.12 mi/kwh in "city" driving
3.12 x 1.1 = 3.4 mi/kwh from the battery to the wheels (ie what the car reports)
93 MPGe / 33.7 = 2.76 mi/kwh in "highway" driving
2.76 x 1.1 = 3 mi/kwh from the battery to the wheels (ie what the car reports)

 

[Motomax]

Actually that is exactly what the EPA does to compute "Miles per gallon equivalent", or MPGe. The correct value is 33.7 kwh worth of energy in a gallon of gas. Since they round off the kwh/100 mi to a whole number in the report the calculation isn't exact (99MPGe vs 100MPGe for the RWD):

SR AWD:
100 mi / 36kwh = 2.77 mi/kwh
2.77 mi/kwh x 33.7 kwh/gal = 93.35 mi/gal equivalent

SR RWD:
100 mi / 34 kwh = 2.94 mi/kwh
2.94 mi/kwh x 33.7 = 99.11 mi/gal equivalent

SR RWD (assuming the actual kwh/100mi is 33.7)
100 mi / 33.7 kwh = 2.97
2.97 mi/kwh x 33.7 = 100 mi/gal

Yeah I know, my joke was about literally converting two gallons of gas to a full battery which is impossible. MPG is a real world result. MPGe is a BS theoretical value used to trick people who don’t understand where the numbers come from.
The only way to accurately compare gas to electric for a consumer is to look at real world cost for the energy used (gas or electricity). No consumer cares about the energy density of gas and there’s no practical application where it is a good reference for electric vehicles ??‍.

MPGe works better if you're also throwing PHEVs into the mix.

It really doesn’t, MPGe is worthless. PHEVs report both gas and electric numbers separately.
They should be reporting m/kWH for electric and MPG. Then you can really compare models as well as compare real world operating Costs.

 

[Mach1E]

Yeah I know, my joke was about literally converting two gallons of gas to a full battery which is impossible. MPG is a real world result. MPGe is a BS theoretical value used to trick people who don’t understand where the numbers come from.
The only way to accurately compare gas to electric for a consumer is to look at real world cost for the energy used (gas or electricity). No consumer cares about the energy density of gas and there’s no practical application where it is a good reference for electric vehicles ??‍.



It really doesn’t, MPGe is worthless. PHEVs report both gas and electric numbers separately.
They should be reporting m/kWH for electric and MPG. Then you can really compare models as well as compare real world operating Costs.

MPGe is kinda silly math wise.

What happens when you divide by zero? (No gallons)

With electricity, I would rather it look like the stickers they put on appliances. “Estimated cost per year.”

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