1st really cold weather drive

[tnt1971]

I did a 240 mile drive today in really cold weather (between 10-15 degrees F). I could not believe the consumption, averaging 450 wh/mile on the first leg, then about 420 on the 2nd. I think I had a pretty strong headwind too (which may explain the lower on the 2nd because I turned north at that point). I was using about 1.5 miles for every mile. For the first two legs I did not have range mode on. On the 3rd leg I did, and that dropped consumption to 380, but I was also traveling at a lower speed.

The posts have great information and I knew mostly what to expect. For new S and potential owners, when it gets that cold the real world mileage is 150-180 (my car is rated at 270) or about 60%. You might get 75% if you turn down the heat and baby it.

The good news is I got normal charge rates at the superchargers. In fact, I think they were the best charge rates I have seen, and I had the car over a hot summer. On the first one I was surprised to hear the battery cooling system come on when I pulled away, even though it was about 10 degrees. It did not stay on long.

To those that posted, thanks for all the great information. Still love the car, but it would make me nervous if the superchargers were more than 150 miles apart in a cold climate.

 

[DarkMatter]

I used to own an ICE that would reliably get 26-28 MPG on the highway. When it was 0F, icy, windy, and snowing I saw my worst tank ever: 13 MPG. When we have charging as ubiquitous as gas stations, this will be no big deal. For now thanks for sharing your experience.

 

[Saghost]

How fast were you driving?

My usual experience in long cold drives is that after 20 minutes or so it starts getting a lot better, and settles to only 10-15% over normal driving. Although a big headwind can make any drive suck energy...

 

[Skipdd]

It's been in the high teens and low 20's for the past several days. And it was very windy today. I've been averaging in the 350-390 range for a mix of highway and urban driving. After reading all the cold weather posts, I've opted to keep the heat at 72, turn on all the heated seats, the heated steering wheel, and pre-heat the car using the phone app. My recollection is that last year I was averaging in the 420-450 for very cold days. And I had the heat much higher without doing the other stuff..

 

[tnt1971]

How fast were you driving?

Low 70s. Speed limit was 65-70 most of the way.

 

[CJPonline]

Between Christmas and New Years day, drove from central IOWA to Chicago. In 10-20 F temps and 75+ MPH, also saw 420-450 wh/mile. However, during one 75mile segment, drafted behind a semi, running 73 MPH, my wh/mile dropped to below 360.

Used AP (1.0), with distance set to 2 car lengths. Road was dry, very little road debris kicked up by the semi.
The 20% range boost added a nice cushion.

 

[mattr2]

Thats about what I am seeing too. I have had my P90D for a few months now and real range is about 60-70% of rated range.

I'm not so lucky on the super charger rates, but I have only charged in SLC. It has been very cold here the last month, but the HIGHEST rate I get at the super charger in SLC is 46 Kw which equals about 142 m/hr. That means at least a 80 minute wait for charging. I am pretty disappointed. The service center tells me its because its cold, but the P85D next to me was in the 130kw range. Hmmmm......

 

[Doug_G]

Tip: in cold weather, drafting trucks really works. (Don't get super close, just stay comfortably behind a large truck.)

Caveat: strong crosswinds may reduce effectiveness.

 

[Sparky]

I drove from SoCal to Park City in December. It was -9F going over the summit near Beaver, UT.
Struggled to get below 550 Wh/mi!
I had roof racks on with skis so my Wh/mi was higher no matter what. This was my 4th winter of driving the S to Park City.
I'm familiar with the cold-weather issues and wasn't too worried but did watch the estimated "% battery remaining at destination", closely.
Does anyone know if Tesla estimates this value using anything more than elevation and posted speed limits? Seems like outside temp would be something they could/should access.
I didn't trust Nav when at the St. George charger, it said I had enough range to continue (plus I knew I was heavy with gear, people and had poor drag). Speed limit was 80 MPH (I drove ~65). Started with Nav telling me 27% estimated range remaining and ended with 6%.
I'm just wondering if anyone has confirmed whether the Nav-system range estimate accounts for higher Wh/mi due to low temps.

 

[Nietschy]

but the HIGHEST rate I get at the super charger in SLC is 46 Kw which equals about 142 m/hr. That means at least a 80 minute wait for charging. I am pretty disappointed.

do you have range mode on or off? if on off the battery could be too cold to supercharge very quick. how long have you been driving before trying to supercharge? just to clear that you did not have any yellow bars on the speedometer that surely kill any fast charge.

but the P85D next to me was in the 130kw range. Hmmmm......

I have not heard of anyone charging a 85 with more than 118KW...
you mean literally "next to you"? you know that the stalls have numbers and letters? 1a and 1b? 2a and 2b. Every of those pairs share one 145KW charger. if the P85 next to you was charging at 115KW you get whats left of it: 30KW.
Try to find a stall pair that has no one charging before you plug in.
The first one always gets the full speed, the second gets whats left.

 

[SabrToothSqrl]

I miss my 1995 Chevy Tahoe 5.7L

City. 12MPG. Highway: 12 MPG
uphill: 12 MPG
Downhill: 12 MPG
Snow: 12 MPG
engine off: 12 MPG
being towed on a flat bed: 12 MPG.

 

[Saghost]

I miss my 1995 Chevy Tahoe 5.7L

City. 12MPG. Highway: 12 MPG
uphill: 12 MPG
Downhill: 12 MPG
Snow: 12 MPG
engine off: 12 MPG
being towed on a flat bed: 12 MPG.

Amazing what happens when you only get to see large chunks of data averaged together...

 

[Rocky_H]

I miss my 1995 Chevy Tahoe 5.7L

City. 12MPG. Highway: 12 MPG
uphill: 12 MPG
Downhill: 12 MPG
Snow: 12 MPG
engine off: 12 MPG
being towed on a flat bed: 12 MPG.

While that is hilarious, there is a point to be made from this for people who are making the transition from gas cars to electric. When a vehicle is blowing two thirds of its energy out the tailpipe and the radiator, the efficiency is already terrible, and minor effects that hurt efficiency are so relatively small, they are hard to see. But for a drivetrain system with very high efficiency, a shift in conditions can knock it down much more and be noticeable.

 

[fasteddie7]

I found that charging up to 80% then charging the last 20% while warming the cabin right before I leave gets me a long way. The trick is to eliminate the "dotted yellow line" that limits regen. When I have limited regen, my wh/mi is much higher than when I'm putting juice back in right from the start instead of 20-30 minutes into the trip.

 

[Saghost]

I found that charging up to 80% then charging the last 20% while warming the cabin right before I leave gets me a long way. The trick is to eliminate the "dotted yellow line" that limits regen. When I have limited regen, my wh/mi is much higher than when I'm putting juice back in right from the start instead of 20-30 minutes into the trip.

I think the battery heater shuts off shortly after the yellow line goes away, which is probably part of the high consumption.

 

[Cyclone]

I think the battery heater shuts off shortly after the yellow line goes away, which is probably part of the high consumption.

I could be wrong and/or it could have changed in v8 (I'm still on v7), but I believe that is the behavior with range mode off. With range mode on, the battery heater won't kick on at all beyond any levels needed to prevent battery damage.

 

[dgpcolorado]

...I'm just wondering if anyone has confirmed whether the Nav-system range estimate accounts for higher Wh/mi due to low temps.

My impression is that it does not. In my experience when running climate control, both AC and heating, the estimate is way off and I've learned to leave a bigger buffer in those conditions.

EVtripplanner.com is a better guide as to what to expect.

 

[ColdRauv]

My impression is that it does not. In my experience when running climate control, both AC and heating, the estimate is way off and I've learned to leave a bigger buffer in those conditions.

EVtripplanner.com is a better guide as to what to expect.

I agree that the in-car NAV and trip usage slope graph does not take into account cold weather (or at least not enough). In winter driving, my true usage graph always falls below the predicted usage graph. My usage with cabin heat and freeway driving speeds seem to average about 450 wh/mi at 70mph, but its always higher during the first dozen miles

(see picture).

 

[siteexperts]

The past week it was ~20-30 degrees in Seattle area. I was always well above 500kw/h (many times I am over 600 and 700 kw/h and for one short drive was actually showing well over 1000kw/h for some reason). I was lucky to get over 100 miles out of a 90% charge on my P85D (rated range once charged is always between 221-226). I have range mode enabled and use the heated seats/ steering wheel.

Once it gets below 30 the car is basically like a Nissan Leaf (use it for errands, would not go on any real drives if I did not have charging readily available as I almost ran out of juice just driving around town and had to charge at a local store for an hour just to get home).

 

[neroden]

The past week it was ~20-30 degrees in Seattle area. I was always well above 500kw/h (many times I am over 600 and 700 kw/h and for one short drive was actually showing well over 1000kw/h for some reason). I was lucky to get over 100 miles out of a 90% charge on my P85D (rated range once charged is always between 221-226). I have range mode enabled and use the heated seats/ steering wheel.

Once it gets below 30 the car is basically like a Nissan Leaf (use it for errands, would not go on any real drives if I did not have charging readily available as I almost ran out of juice just driving around town and had to charge at a local store for an hour just to get home).

You're encountering the "startup cost" of warming the battery.

The fact is that, in an S85 wiwth 265 miles of rated range, you can drive about 175 miles at 10F, if you drive continuously. I've done this.

However, the usage will be *massive* for the first ten minutes, to warm up the battery. If you drive 10 minutes to work, are at work for 4 hours, drive 10 minutes to lunch, eat lunch for 30 minutes, drive 10 minutes back to work, are at work for 4 more hours, drive 10 minutes to go shopping, go shopping for an hour, drive 10 more minutes... you'll get that 1000 kwh/mi usage for every single 10 minute journey and use up your range really fast. (Exception: if you park in a heated garage.)