Ben Sullins of Teslanomics teamed up with TezLab to get a better handle on what impacts EV efficiency and how Tesla owners (or really any electric car owners) can improve range.
Electric vehicle efficiency is basically how many miles you get compared to what your "supposed" to get. So, if you should get 200 miles on a charge but you get 150, that's 75 percent efficiency. If that same vehicle got 250 miles on a charge, then efficiency is up at 125 percent.
Weather affects EV efficiency much like it affects ICE cars, but there are some marked differences. The folks over at TezLab in Brooklyn measure range using a somewhat complicated system, but since they do the hard work for you, there's no need to get into the specific details.
Let's take a quick look at what the team discovered:
Most everything the study found can be related back to temperature
it's widely known that cars are less efficient when it's cold, however, the study shows that temps over 80F also have a negative effect
Parking in a windy area can drain more range than you may think
Cold temps increase charging times
Sullins goes into a much greater level of detail regarding specifics in the video. Although many EV aficionados are well aware of this type of information, the general public isn't necessarily apprised.
Video Description via Teslanomics by Ben Sullins on YouTube:
If you already own an EV, you know that your rated range, that is how far you can travel on a single charge, never is as advertised.
Today I have a special episode for you. I’m here in Brooklyn with the TezLab team, and we’ve been digging into what effects your battery range and what you can do to improve it.
Efficiency for a Tesla, or rather any car really, relates to the distance you expect to get from your fuel compared to what you get. So if your Tesla is telling you you’ll get 200mi on a charge and you only get 180 miles, that’s 90% efficiency.
Conversely, if you got 210 miles on a 200 mile rated charge, that would be 105% efficiency.
So in this way, your car can be wildly inefficient or quickly get over 100% depending on some key variables.
EVs and ICE cars are similarly affected by things like hills however that’s where the similarities end. Most EVs, like Tesla’s, have regenerative braking which slows the vehicle down and recharges the battery at the same time.
This is extremely helpful when you’re headed down mountains where your car can regenerate loads of power.
The way Tezlab measures this is by looking at the distance traveled by the range difference reported from the Tesla API. This can get a bit tricky, so I’ll spare you the details and suggest you check out the app where you can see the efficiency for every trip you take as well as other factors like Phantom Drain.
// When is efficiency the worst?
When looking at the data from all the cars in the fleet, it became immediately apparent that the correlation between temperature and efficiency was strong. This means that if you’re in a colder climate, you will likely get less range out of your car then in the warmer climates.
For those of you living in these areas already, this is a no-brainer. It wasn’t until this we analyzed this data however that we realized it also affects warmer climates.
In fact, over 80 degrees F seems to have a negative impact on the driving efficiency as well. Now, both of these may seem obvious that you’re using our heating and cooling, but there’s more going on than just the interior of the car that could be affecting your driving efficiency.
// Insight #1 - Avoid parking in a windy area
Wind seems to have an impact on the phantom drain as well. This is again due to temperature, but even over a short period, a cold, windy area can zap the energy from your Tesla.
// Insight #2 - Below 50 degrees efficiency falls off a cliff
Once the temp drops below 50 degrees, F is when you need to be conscious of your driving habits and charging. Data suggests that you’ll lose an additional between 10 and 20 percent with a median efficiency around 60% overall.
// Insight #3 - Expect Charging Delays
The last thing we’ve learned is about charging times. Again it has to do with temperature, and the data we have suggests that in colder temps you’re going to spend extra time charging.
If you’re using a level 3 charger like a Supercharger and are used to topping up in about 45 minutes, you may need more like an hour and a half. The data we have for this vary greatly, so it’s hard to say exactly what to expect, but the trend is clear, as the temp drops the charging times go up.
As time goes on, we’re going to continue to monitor this and develop more insights to help you get the most out of your Tesla. If you haven’t already get the TezLab app from the link in the description above and start monitoring your efficiency today.
