If you’re stuck in a two hour or more traffic jam in an electric car (e.g. Tesla vehicles) with lights on and heater, don’t you worry about losing all electricity?

Q. Q. Don’t worry if you lose all your electricity if Tesla cars have lights on and heater.

A. I have no worries about losing power or range in traffic in Metro Denver.

But why? Electric vehicles are more efficient at slower speeds than those on the highway. My Tesla Model 3 has a greater range because of traffic jams.

Weather conditions can be severe, so highway speeds will slow down. This more efficient driving speed compensates for higher heating requirements.

Maximum range is at speeds between 20-50 MPH. The range is usually reduced by speeds below 20 MPH and above 65.

But what if it is really cold?

As Tesla recommends, I make sure my car is plugged in when it’s parked. Before leaving the house or charging my car, I pre-cool or heat up.

The heater and other aux system use mains power when you’re plugged in. You could lose as much as 10% of your range for melting snow and getting the car back to normal operating temperature.

To make up for heater use, I also set the winter charge limit higher.

Now, WHY should I be worried?

My Tesla Model 3 has an EPA rating of 310 miles highway/city combined.

  • These are the conditions and the resulting mileage
  • Extreme weather conditions–about 200 mi in the worst cases–no preheating or hills (round trip), in freezing rain, snow, ice and freezing, with a headwind component. Use windshield wipers/washer and seat heaters. Defrosters at the highest speed possible in these conditions. This is a 35% maximum range loss. It’s the worst case scenario for me with the Tesla Model 3 Long Range. I have also seen 50% in other EV Models.
    • Important: The ranges that I have shown are absolute and can go from 100% to zero. It is bad for the battery to go below 20% and for it to be 0 charged. Expert Tesla drivers advise that you should not drive below 20% for more than 62 miles. My Tesla’s battery meter changes from green to yellow at 62 miles. Add 62 miles to the total range of 200 miles and you get 138 miles of ‘comfortable range’. I keep my Tesla charged at 80% and 20% for normal driving. In severe cold, I can drive 140 miles. I don’t plan on driving to the Supercharger while on a road trip. I will charge my car immediately. My car is the 310-mile Tesla. Some Tesla’s get 400-miles. However, most EVs get much less.
    • This report on bad weather in Chicago reports 36% range loss. Range in winter really terrible – Chicago
  • Interstate driving–about 250 mi if driving at highway speeds–60 to 80 MPH. In bad weather and extreme temperatures, not
  • Average driving distance is 300 miles. Driving speeds are not exceeding 70 MPH. My car has averaged 283 miles per year so far, with lots of winter and high speed driving.
  • Good conditions–about 350 to 400 miles if it is kept below 60 MPH with no stopping or hard acceleration, and no net uphill. It’s good weather, not too hot.
  • Hyper-miling – Maybe 600 miles if it stays below 30 MPH with accessories off and good weather/ideal circumstances.
    • A German team drove 622 miles on a Model 3 for 28 hours using autopilot. That’s 22 MPH. Denver: A team of two drivers drove around the airport at 25-30 MPH, with the air conditioning off. They managed to get 606 miles. They had to stop at stop lights and red lights on regular roads.
    • In October 2019, I had 700 miles in a single charge. This was on city streets in FL at 20 MPH.

NOTES:

    • Your mileage may vary. I drive mainly in Colorado, which has low humidity and thin air. This makes it easier for the car. Chris Eddy, who pointed out that Denver has thinner air than many cities, is a big thanks. Thinner air means less drag. Chris calculated that I might get a 10% increase in range. This would only apply to highway driving. UPDATE October 2019, I tested the car near Texas sea level and found that ranges were slightly lower than Chris predicted. My lifetime efficiency was not affected. Perhaps I wasn’t there for enough time. You will also find less fogging of windows, which requires defrosters.
    • If you don’t drive a Tesla Model 3, your mileage might vary. Today, I was able to see data from the Model S. It was very similar to what my car did in stop-and-go traffic. (Nov 2019).
    • If you’re going uphill, YMMV One Model S driver claimed that he lost more range in traffic jams going uphill than he expected. (Nov 2019)
    • The numbers above represent a range of full to zero charges, which is probably not something you want to do. Add 60 miles to the above numbers if you need to reach your destination with 60 miles left.

You can slow down if you run out of power!

  • You will be very low on battery while on a trip. The Tesla will tell you. All you need to do is slow down.
  • I was driving along I-70 in Kansas, a few months back in heavy driving rain. The headwind was apparently 30-40 MPH. I had heater, defroster, and wipers set to max. The car was traveling at 70 MPH, but the wind was causing the AIRSPEED to drop to 100-110 MPH. The result was that I was using too many batteries to get to the next station. I was advised by the car to slow down to get to the next charging station. The car recommended that I keep to 60 MPH. I did so and made it to the next charging station with plenty of power.

Tesla’s low speed reduces wind and rolling friction, so it is less efficient if you are stuck in traffic.

Teslas experience traffic jams that increase in range. The best results are achieved when Teslas move at 20-40 MPH.

  • While cold temperatures can drain some power, what really saps it is when there is heavy snow and ice downpours. In the worst conditions, the car may lose about 35% of its total range. This is approximately 100 miles less than my normal range of 310. Winter heating with heaters and accessories is more than 20%. On the hottest days, A/C is more than 10-15% (in Denver with Window Tint). Phoenix or Vegas would have more.

EXAMPLE

I’ve been stuck in stop-and-go traffic more times than I can count during my 40 mile commute to work.

If traffic is good, I usually leave my house with 234 miles range (75% fee) and arrive at my destination with 194 miles range (exactly 40). This averages between 55-65 MPH. The car has 154 miles range when I return home. It takes me 1 hour 50 minutes to recharge it.

If traffic is bad and it is stop-and-go most of the time, I can get as low as 20 MPH, which makes my 40-mile trip take me 2 hours. My mileage increases a lot in this situation. The Tesla is on Autopilot, but it stops a lot, waiting for it to move. It uses almost nothing when it’s stopped. It is only using very little juice when the car is moving at 20 to 40 MPH. It can appear that I have only covered 20 miles of the 40-mile distance to get me to work. This means I get back half of my range. If I’m using heaters and accessories, I might be using 20%. The heater is often more expensive than the slowing down.

BONUS PIC

This is the Tesla camera defroster melting through ice so Autopilot works.

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