Winter driving with heater efficiency

Winter driving with heater efficiency

So I've been struggling with my overall efficiency in the winter. Averaging well into the 330's+ at roughly 20 degrees. Some say that's normal some say that's way to high. Then of course the "don't use the heater," "use heated seats only," "pre-condition the car before leaving."

I've tried the no heater thing. And it gets cold quick and even with my coat on it's just not pleasant. But I don't need it a thousand degrees either. So my thought process was I'll set the heat to auto 68. Should keep the heater usage low and I won't be miserable. Car efficiency really didn't change at all, still in the mid-300s. So I decided to tinker with heater and set everything manually, my gosh that improved my efficiency greatly, and I have it set warmer then I did before!

Manually set to 70, fan speed 1 (or 2 if it's in the single digits), vents+defrost and I've been averaging under 280wh/mi.

I've yet to see anyone say anything about moving off auto and manually setting the temp (or maybe I've just missed it) but for any new owners out there like me experiencing winter for the first time maybe this will help you!

EVRider | 18. marraskuu 2019

Unless there’s a chance you can’t reach your next charging stop, why worry about it? Set the heater to whatever’s comfortable and enjoy the drive. I really don’t get the obsession some people have with their wh/mile performance, but to each their own.

jebinc | 18. marraskuu 2019

Most times, I leave the heater off and just use the seat warmer. Uses much less juice than an electric hot air heater and fans.

SalisburySam | 18. marraskuu 2019

@EVRider, +1. I’m a temperature/comfort wuss in every regard, i.e., lots of A/C in warm weather, all the heat I want in cold. That’s why for me range is king, to ensure I can feed my comfort habit. My Auto is set at 70ºF and that’s with seat heater too. With passengers, everyone has their seat heaters on. Def wish I had the steering wheel heat that my LEAF has. Haven’t even looked at my wh/mi in months, though I do see lifetime of 246 occasionally, never seems to vary much. Car delivered 07/18 so been through one winter so far. Getting the Model 3 allowed me to forget about the hypermiling techniques necessary to drive my 2012 LEAF anywhere.

brknoth | 18. marraskuu 2019

Im going to try that myself. The reason it's useful info @EVRIDER is it's definitely worth it if you can skip a charging stop on a long trip.

howard | 18. marraskuu 2019

If you can’t set the temp to be comfortable you bought the wrong car. It is simply unacceptable to make cabin comfort sacrifices just because you drive an EV. An expensive car at that. I never take mine off auto. It is set at 72. Set to desired temp and enjoy!

M3D | 18. marraskuu 2019

This is interesting. How did you test? Is 70 your comfort temp or the most efficient temp. i.e. is 68 manual fan on 1 more efficient? Was it 330 on Auto and 280 on Manual?

coleAK | 18. marraskuu 2019

The auto climate setting works best in the cold from what I’ve found. This weekend 8” of snow, 2 days of unplowed roads, and temps in the 20sF. ~450wh/mi in the Tesla and 10mpg in my LX570. I’ll take the Tesla with a smile.

Like others have said. Set the heat to where you Are comfortable, not worry about Wh/mi and smile.

Or if you are ultra frugal you could try this?

PixelatedDensity2 | 18. marraskuu 2019

@evrider - For my daily commute you're right not a big deal. But I do take trips on the weekend to rural areas of ohio. Which means zero charging (lvl 2 or 3). So making a round trip in the winter has my anxiety at a 10. I've made the trip a couple times with less then 20 miles of range left.

@MSD - honestly this is super non scientific - I was on a short trip one hour each direction and I started to play with the temp settings, almost immediately it dropped from 330 area to 280s. I have since made several short trips in the span with the same settings and have had great success with it. I tried to keep all the variables as close to the same as possible. My lifetime was sitting in the high 290s climbing a bit almost everyday. And as of this last week even though it's getting colder my efficiency has gone up greatly.

skygraff | 18. marraskuu 2019

I’ve given up on auto because it runs the fan too high and fails to defrost the windshield in a timely manner. I agree that seat heat just doesn’t cut it unless I’m bundled and wearing gloves which I prefer to avoid on drives longer than a few miles.

For what it’s worth, I typically go with 68-72 and have all three vent directions employed with a fan speed of 1 (unless defrost needs to be more aggressive). I do try to preheat and will occasionally use the seat heater (wish it didn’t save the profile each time). Unless I’m on a road trip, I don’t worry about the efficiency since it all averages out with my summer driving (don’t use auto there much either).

Probably my biggest annoyance is that the local electrical utility’s pricing goes up in winter (expected the opposite with lack of AC use but guess heat is just as lucrative for them) so my charging costs are going up at the same time the efficiency is going down. Not to mention the battery warming energy consumption. Still costs less than fuel in an ICE and I’m not having to gas up in the cold.

hokiegir1 | 18. marraskuu 2019

On a recent long trip home, We opted to keep the heater on 68-70 with the fan on 3. As our anticipated arrival SOC got under 5%, I started to panic a little (we were less than a third of the way there and had started at 25% on arrival) I turned off the heat for the next 20 miles. Our arrival SOC crept back up to 9%. We were still reasonably comfortable, but I toggled back and forth between off and on based on the projections. We ended up arriving at the supercharger with about 7%...and we charged a bit more than our usual buffer before the last leg.

Knowing how it reacts on short trips does help plan for longer trips. While I'm of the "I don't care in day to day" camp, it's helpful to know I need to plan for about 30% more usage for distance travel if I want to be comfortable.

PixelatedDensity2 | 18. marraskuu 2019

@hokiegir1 This was almost exactly a style trip I was alluding too. Again small sample size here but I've been preheating the cabin before I leave and setting heat to 70 w/ fan at 1 has kept the cabin very comfortable without the need to toggle and seems to use little energy this way.

skygraff | 18. marraskuu 2019

Yeah, I forgot to mention that I tried the toggle thing during my road trip in the mountains last year and it really didn’t make much of a difference vs keeping a steady state of 70 with manual fan at 1 (occasional defrost and seat heat bursts).