# Forums

## How many km's can Tesla Model S (2013) travel with 1 kWh?

I would like to know how much kilometers would some electric car travel with one kWh.
How can this be calculated?

I took a look at wikipedia's "Miles per gallon gasoline equivalent" page:
(I can not post the wikipedia link, because then my post gets blocked)

In there they use MPGe as units, but also kWh/100 miles.

Is it possible for some specific type of car for example Tesla Model S (2013) mentioned from the same wikipedia page. to calculate how many kilometers will it travel by the use of a single kWh?

Which mpg-e category would one need to take in order to calculate this?
EPA rated combined fuel economy, EPA rated city fuel economy, EPA rated highway fuel economy?
(for Tesla Model S (2013) for upper three categories: 95 mpg-e, 94 mpg-e, 97 mpg-e)

1 mile = 1.609344 kilometers

Sin_Gas | 14/03/2015

Hello
First, let me tell you that MPGe is not very useful. Its poorly defined and gives numbers that bear no reality. You will find this if you investigate them on most cars.

As for your question, at hyway speed, a model S will travel about 295 miles, at 70 deg F, on flat roadways on a full charge. A full charge is about 76 KWH (the other is a buffer to get to 85). So that is 3.88 miles or 6.25 Km per 1 Kwh of electricity.

Sin Gas

issworld2000 | 14/03/2015

Thank you Sin Gas.
Is this MPG-e's inaccuracy only related to Tesla models or to any other electric car models too?

According to average MPG-e's (combined, city, highway), Tesla Model S (2013) is suppose to travel 4.717 kilometers per 1 kWh, which is far less then what real data you showed me, present:

kWh/100 miles = 3370/MPG-e

EPA rated combined fuel economy, EPA rated city fuel economy, EPA rated highway fuel economy average (from wikipedia's "Miles per gallon gasoline equivalent" page)

(95 MPG-e + 94 MPG-e + 97 MPG-e)/3 = 95.33 MPG-e

3370/95.33 MPG-e = 35.35 kWh/100 miles = 0.3535 kWh/mile = 353.5 Wh/mile

0.3535/1.609344 = 0.212 kWh/km
For 1kWh: 1/0.212 = 4.717 km

----------------
I googled a bit and found a lot of sources stating that Tesla Model S, takes 340 Wh/mile, which close to the 353.5 Wh/mile calculated above.

Rocky_H | 14/03/2015

The MPGe is hard to convert to anything useful. The car's energy display and most owners' data is expressed in terms of Watt-hours per mile. A kind of calm level driving will be around 300 or a little less Wh/mile. Higher speeds or if you are running more heat in the car will probably be consuming more like 350 to 400 Wh/mile. I think the LEAF and some other electric cars display it in the inverse, how many miles per KWh.

issworld2000 | 14/03/2015

Thank you Rocky_H.
Then what calculation approach would you recommend for calculating how much miles/kilometers an electric car travels using 1kWh?

Rocky_H | 14/03/2015

That's why I said "inverse". At 333 Wh/mile, that is 0.333 kWh per mile. Therefore, take the inverse, and that is 3 miles per kwh.

issworld2000 | 14/03/2015

So you giving a general assumption that on average most electric cars, travel 3 miles per kWh?

Sin_Gas | 14/03/2015

issworld2000

What I calculated was how far a Tesla would travel at a constant highway speed of 65 mph, 70 deg F, and no hills.

The EPA numbers and the MPGe numbers include 5 different driving cycles of combined city and hiway driving, which gives somewhat less.

MPGe does not seem to relate to any car I have tried to use it for. I have only used it for cars with battery and gas.

The Tesla web site has a very complete section on its web page about range for its vehicles.

Sin Gas

Svenssons | 14/03/2015

I find the use of MPGe just stupid. Electricity does not come in gallons. What is interesting is how much energy (usually measured in kWh) a car need for a specific distance. It does not matter if it's an electrical car or an ICE-car.

One US gallon of gasoline is about 36 kWh of energy and one US gallon of diesel is about 41 kWh of energy. If a gasoline car have 20 MPG (like Mercedes S class) it will go 20 miles while consuming 36 kWh. This mean it will go 1.8 miles per kWh. Tesla Model S will go about 3 miles per kWh. These numbers can be compared and relates to both ICE-cars and electric cars. It also shows that electric cars are much more efficient than ICE-cars.

Using gallon (US or UK gallon...) is just stupid then one talk about an electric car. I hope and think that the numbers for miles per kWh or kWh per mile will be used as standard for all cars (not just electric cars) in a near future. ICE-car owners would know that not only have the price at the pump gone up a lot compared to 20 years ago but the amount of energy per gallon have in fact decreased because ethanol is mixed in with the gasoline.

Brian H | 14/03/2015

The 3 mi/kWh is a general range. It varies so much with conditions and speed, etc. that there are only specific answers for each car in each kind of driving. How long is a string?

Svenssons | 14/03/2015

I calculated the 20 MPG wrong, it should be 0.56 miles per kWh for the ICE car compared to 2.6 miles per kWh for Tesla taking the number from this site:

http://en.wikipedia.org/wiki/Tesla_Model_S

Svenssons | 14/03/2015

Yes, the 3 miles kWh is general range just like 20 MPG for a Mercedes S class. The range and fuel consumption varies just as much on a ICE car as on an electric. The string for Model S is about 2.6-3 miles per kWh and for Mercedes S class about 0.56 miles per kWh if you are talking about EPA strings...

Mike83 | 15/03/2015

In my thousands of miles of driving I historically used around 300kWh/mile but by various driving techniques using 200 kWh or less is possible which could give you 400 miles/charge. In my case recently 245 works the best since I do 240+miles trips. But if you do 0 to 60 or higher in 4 or 5 seconds you will use more kWh just like drag racing using gallons/mile but you don't have to rebuild your engine after performance runs.

Basically it is how you drive that determines the kWh's you use up.

issworld2000 | 15/03/2015

Thank you for the replies. All of you.

DTsea | 15/03/2015

5 km per kWh. Very simple. Same as 3 miles per kWh.