Mile per gallon formula?

[etracing]

I did a search but did not find an usable answer.

Is there an excel formula that can give me a mile per gallon equivalent for our car?
I have see some graphs but nothing that I could put in real time numbers.

Variables would be :
Miles per KWH.
Local gas prices.
Local price of electricity.

Thanks!

 

[TickTock]

Miles_per_gallon = miles_per_kw * dollars_per_gallon / dollars_per_kw

 

[LTLFTcomposite]

Speaking of formulas (formulae?), another one answers the question "If the electricity for an EV came out of an e-gas pump, what would the pump price be per gallon?"

For this you have to estimate what the MPG would be on a gas car comparable to the Leaf.

(centsPerKwh / milesPerKwh) * comparableCarMilesPerGallon

I use 25mpg, 11 cents kWh, and 4 mile/kWh... so I tell people for me the Leaf is like getting gas for 69 cents a gallon.

 

[ElectricVehicle]

See this thread:
Public L2 charging $1 - 1.50/h reasonable?
http://www.mynissanleaf.com/viewtopic.php?f=12&t=8139" onclick="window.open(this.href);return false;

 

[N1ghtrider]

I am not an engineer or a mathematician (Hell, I got through 4 years of college without a single math class and never took Alegebra in high school), but here is the way I do it. My electric bill shows that I pay 11.7 cents per kwh (taxes included). My car averages 5.2 m/kwh. That is 192.3 kwh per 1,000 miles. My electricity for the Leaf costs $22.50 per month, or for each 1,000 miles. At $4.00 per gallon, I could only buy 5.625 gallons for $22.50. If 5.625 gallons would take me the 1,000 miles I am driving, that would be 177.78 mpg.

 

[waitingforaleaf]

I am not an engineer or a mathematician (Hell, I got through 4 years of college without a single math class and never took Alegebra in high school), but here is the way I do it. My electric bill shows that I pay 11.7 cents per kwh (taxes included). My car averages 5.2 m/kwh. That is 192.3 kwh per 1,000 miles. My electricity for the Leaf costs $22.50 per month, or for each 1,000 miles. At $4.00 per gallon, I could only buy 5.625 gallons for $22.50. If 5.625 gallons would take me the 1,000 miles I am driving, that would be 177.78 mpg.

You just need to add in charging efficiency. Which if you calculate conservatively as 85% efficient, then it would be 226.2 kwh (i.e. 192.3/0.85) per 1,000 miles. Thus, it would be $26.47 a month. At $4.00 per gallon, you get 6.6175 gallons, therefore it would be 151.11 mpg.

 

[LTLFTcomposite]

You just need to add in charging efficiency. Which if you calculate conservatively as 85% efficient, then it would be 226.2 kwh (i.e. 192.3/0.85) per 1,000 miles. Thus, it would be $26.47 a month. At $4.00 per gallon, you get 6.6175 gallons, therefore it would be 151.11 mpg.

Hey the gas-powered world never factors in all the external costs, why should we?

 

[waitingforaleaf]

Hey the gas-powered world never factors in all the external costs, why should we?

Because this wouldn't be exactly an external cost? The charging efficiency here refers to wall-to-wheels (i.e. I made the assumption that he used dash-to-wheels when he was referring to 5.2 m/kwh, if this assumption is incorrect then his numbers stand). If you assume the Nissan Leaf's charger to be 85% efficient, then his actual electricity bill would reflect a charger for 226.2 kwh and not the 192.3 kwh.

 

[N1ghtrider]

That's right; I used the Carwings dash-to-wheels numbers for the 5.2 m/kwh. Figuring the 85% efficiency and even using "cheap" gas at $3.85 per gallon, that would be the equivalent of 16.8 gals taking me 2,445 miles, or 145.5 mpg equivalent. Not too shabby.

 

[kpkimi]

I created an Excel spreadsheet with the following information:
A3: Cost of gas / gal B3: 4.25 (your input goes here)
A4: Cost of elec / kwH B4: 0.326 (your input goes here)
A5: Car mi/ kwH B5: 4.5 (your input goes here)
A6: Charger efficiency B6: 0.84 (from what I've read, .84 for 240V, .73 for 120V)
A8: Equivalent miles/gal B8: =(B3/B4)*B5*B6
My answer is 50 miles / gal. Electricity in Honolulu (32.6c/kwH) is 3X the US average of 11.5c/kwH. Even so, 50 mi/gal is 3X better than what I was getting with my other car.