Stuck in traffic

[Super Snake]

I am new here and will have my P85D next week. I have not seen this written about but all of this talk of less than promised range got me to thinking.
Has any one been stuck in traffic, I mean for any real length of time? In the middle of winter with the heat on, how long can the car sit? With all the pictures of cars stuck in bad weather and behind lane closing accidents, can I expect anxiety about not getting to my planned charging station?
Any one have any experience with this? Is traffic jams part of your trip planning?

 

[jerry33]

If the car is already warm, maintaining temperature doesn't take that much energy. The plan is to have 25% of range left between charging stations to cover the unexpected. Use EV Trip planner to calculate the effects of hills, temperature, etc.

 

[jayman]

You don't lose much milage just sitting there heating the car. Not as much as you would think anyway. Range anxiety is synonymous with newbie. Not meant to offend but range anxiety goes away over time...

 

[efusco]

It certainly depends upon how much charge is left, but the answer is a VERY long time. It would certainly help to put the car in Range Mode and turn down the heat and utilize the seat heater, but unless you're running very very close on charge on a long trip you're going to make much more efficient use of your "fuel" thank you would in an ICE vehicle.

 

[Zarwin]

much more efficient use of your "fuel" thank you would in an ICE vehicle.

I was going to point that out.. would rather be stuck on a snowed in interstate in a Tesla than an ICE. For the same amount of 'fuel' in the tank, the ICE will run out before the Tesla. Only exception may be a hybrid like the Prius which switches the engine on and off periodically to heat the fluid heating the car. I've let our Prius run for hours parked in the bitter cold with heat on and it didn't seem to use hardly any fuel.

EDIT:
Oh, and not directly related to the thread, but something I have in my car that my son loves is a 12v heated blanket (link below). This would be a great supplement to the heated seats, allowing the cabin heat to be set down really low to save power.

Amazon.com: Trillium Worldwide Car Cozy 2 12-Volt Heated Travel Blanket (Navy, 58): Automotive

He sits in the 'way back' jump seats which don't warm up as quickly as the rest of the car, but this small heated blanket is more than enough to keep him cozy back there, and the cord is long enough to reach.

 

[EarlyAdopter]

At steady state (i.e. the car's already warmed up) the heater draws 1kW to 2kW. When idling the motor uses 0 energy and all of the rest of the car systems use a negligible amount (maybe 0.3kW).

So, on a half empty 85kWh battery you could sit in traffic for 20 to 40 hours with the heater on.

By comparison, a gas car can only idle for 12 hours or so on a _full_ tank of gas, so only 6 hours on half a tank.

This is one place electric cars have a HUGE range advantage over gas cars.

 

[jamieb]

This is one place electric cars have a HUGE range advantage over gas cars.

Not to mention the elimination of any carbon monoxide risk if you end up falling asleep by the side of a road while snow accumulates.

 

[BrianC]

Bjorn Nyland has shown a few times him sitting for around a hour waiting for a convoy to tackle a mountain pass, only lost 9 miles or something like that... would have to go check the videos to give a 100% answer.

 

[N4HHE]

Bjorn Nyland has shown a few times him sitting for around a hour waiting for a convoy to tackle a mountain pass, only lost 9 miles or something like that... would have to go check the videos to give a 100% answer.

9 miles is approximately 2700 Watts which agrees with EarlyAdopter's 1000 to 2000 plus 300 or so overhead for the rest of the car.

 

[EVSteve]

At steady state (i.e. the car's already warmed up) the heater draws 1kW to 2kW. When idling the motor uses 0 energy and all of the rest of the car systems use a negligible amount (maybe 0.3kW).

So, on a half empty 85kWh battery you could sit in traffic for 20 to 40 hours with the heater on.

By comparison, a gas car can only idle for 12 hours or so on a _full_ tank of gas, so only 6 hours on half a tank.

This is one place electric cars have a HUGE range advantage over gas cars.

Wait a minute. Only 12 hours on a full tank of gas? Where exactly is this from? A Class 8 tractor trailer with a 12.7 liter engine idles at a gallon per hour. Thats around 3 times the displacement of the average car. You're telling me the average car is going to run through the same amount of fuel as a tractor trailer? Quick search indicates around 1/3 gallon per hour. On a 16 gallon tank that equates to roughly 48 hours.

 

[drrhm]

No ways a normal ice car can idle for 48 hours on 16 gallons. I'd estimate about an hour a gallon tops for a small 4 cylinder car.

 

[BerTX]

Wait a minute. Only 12 hours on a full tank of gas? Where exactly is this from? A Class 8 tractor trailer with a 12.7 liter engine idles at a gallon per hour. Thats around 3 times the displacement of the average car. You're telling me the average car is going to run through the same amount of fuel as a tractor trailer? Quick search indicates around 1/3 gallon per hour. On a 16 gallon tank that equates to roughly 48 hours.

Also, diesels use less fuel to idle. My diesel Jeep Liberty would (theoretically) idle for 200 hours on a full tank...

 

[jkliu47]

Not to go OT but on a similar line of thought what are the estimates for when we get stuck in traffic on HOT days. With the A/C on does the same advantage over an ICE car prevail?

 

[EarlyAdopter]

Diesels use way less fuel at idle than gasoline engines.

The A/C uses considerably less energy than the heater as it only needs to move heat from one place to another. The heater needs to generate heat. The A/C uses 1kW tops on max, so you'd be able to run it for several days.

 

[jerry33]

Not to go OT but on a similar line of thought what are the estimates for when we get stuck in traffic on HOT days. With the A/C on does the same advantage over an ICE car prevail?

Depends on the car. If the A/C compressor runs using a pulley on the engine, it will reduce the time that the vehicle can idle. If it's like the Prius then it's an electric variable speed scroll compressor--similar to the Tesla. The electric compressor can pull as much as 3.5 kW, but normally pulls far less. So vehicles with an electric compressor have a big advantage over vehicles with a pulley driven compressor. A/C in the Tesla is far less demanding than heat in the Tesla.

If you live in Winnipeg or some similar place where -30 is frequently seen and you drive outside the city, a space blanket the seat heaters should keep you warm for many days (you'll die of dehydration long before you'll freeze). In an ICE vehicle you carry blankets and a candle as your life expectancy if the engine dies is about 30 minutes.

 

[Zarwin]

Just another data point, while a different vehicle, I had a Leaf for several years before getting the Tesla and the Leaf has a display showing the energy usage of the HVAC specifically. On a hot day the AC on a Leaf will pull up to 3kw initially and after the cabin is at temperature, drops into the 250 watt range. Amazing how little is used after the car is at temperature. Also the Leaf would limit the initial draw to 1.5kw if parked, which I assume is due to the reduced air flow over the radiator.

 

[Super Snake]

Thank you everyone for your input. That puts my mind at ease!

 

[jkliu47]

Thanks for the info guys.

I am Hong Kong/China for the holidays, and have sighted at least one Telsa a day in Central HK island since arrival. My wife even incredulously noted that some of them are being driven by chauffeurs!

Now I have credible facts to push back against the FUD going the rounds in Mainland China and Hong Kong, that the Tesla would run out of battery if its ever caught in one of the ubiquitous traffic jams on the highways between major Chinese cities. So its strictly only an urban 'toy' for the well to do.

Another one btw is that the Tesla would be inoperable if it goes out of cellular range when travelling cross country in China. :biggrin:

 

[Zarwin]

Another one btw is that the Tesla would be inoperable if it goes out of cellular range when travelling cross country in China. :biggrin:

Wow, amazing that people will believe something so incredibly stupid ... then again, the rare occasion I visit facebook reminds me there is no limit to stupidity.