Sorry to post a question that is a bit self-serving, but I figured that this is a common route for many so an answer to me may help a lot of others. I considered posting this in the winter driving thread but they are so many pages deep on that I think it would get a lot less traffic thus a lot less comments. Also, this involves issues of both driving and battery so where to post was a bit of a quandary, I settled for here. If the mods think it best placed elsewhere, feel free to move it.
I'm soon to be taking ownership of a 60 kWh Model S (Woohoo!) and in late February I am travelling to Tahoe from the South SF Bay Area. This will be a drive at night, leaving after 7 pm. The temperatures will likely be freezing or even below. Additionally, the route involves chain controls if snowy, so there is a good chance that I will need to use them for the drive. And oh yeah, it is a 6000' climb straight up the mountains.
Getting to the Folsom supercharger will be no problem. But with the low temps and the uphill climb to Tahoe, I have some concerns with the effects of cold and altitude on range. I know people have done this sort of thing with Roadsters in the past but I'm not sure if has been done in the dead of winter at night with chains.
I found a recent report on either this or the main Tesla Forum that I thought may be useful for planning so I saved it to my hard drive but I cannot now find the post and I did not copy the author so whoever you are, thank you. They went up to Tahoe with an 85 kWh pack and noted the following:
"Took a trip from SF to Tahoe this weekend, with a stop at the Folsom supercharger in each direction. Although it was definitely a learning experience, the lessons mainly reinforced things I've heard said again and again about EVs... but which hadn't really sunk in without experiencing them.
1) If the temperatures are low, you really, really must plug in. -- During the first night that we were there, the temperatures sunk to -8F (negative eight), and the battery lost 30 (thirty) miles of range overnight while keeping itself warm. Every time you put the car in park while in cold weather, the car warns you and suggests that you plug in... Don't Ignore this Warning.
2) Climate control and primarily-uphill driving can cause the battery range to be severely over-reported. -- The drive from Folsom to Tahoe gains 6000 ft of elevation: in order to drive the 100 mile distance, we used 190 miles of charge, meaning that we arrived with about 80 miles to spare. I had originally been planning to not charge in Tahoe at all, but due to point (1), it became absolutely necessary.
3) The superchargers are freakin' awesome... but they are not an alternative to charging overnight at your destination"
So this is helpful but worries me from the 60 kWh battery side of things. People are reporting that a range charge in a 60 reads out as 190 miles ish. This MS driver I quoted has reported that this was the number of miles pulled from the battery to make this drive, and it appears that this was with no chains on a clear road.
A number of variables come up in this scenario:
1) If you have on chains, how does the affect range? On the one hand I would think it would decrease range (via efficiency), but with chains you must drive much slower, which increases range. So with a combination of loss of efficiency but gain in range from speed then applying this to an uphill climb, what is the end result?
2) Clearly going from Folsom to Tahoe on a single charge in a 60 would appear to be cutting it quite close based on this report. Any others have reports to share? One thought I had was driving from Folsom to Auburn to use the Clipper Creek 70 amp J1772 for another quick topoff to add a margin of safety, as it is the last high amp charger after Folsom before Tahoe on the route AFAIK. BUT, it is really not all that far from Folsom and that leaves a lot of driving before Tahoe. So would it be enough of a margin to not run out of juice before arriving if I end up in stop and go chain driving on the way up? If I do need to use the Clipper Creek EVSE, anyone have experience with how to get access after hours?
3)Upon arrival to Tahoe, there aren't many options for charging. I happen to be lucky enough to be going to the Ritz-Carlton for work for this trip, but although they have plans to install a 240 volt plug, they don't have one yet. They can guarantee me a standard wall outlet though, and I will be there for 3 nights with no driving in the mean time leaving me about 60-65 hours of continuous charging. But this would be outside in the freezing cold so a lot of the power would likely be lost to keeping the battery warm. The way back is mostly downhill after a brief initial climb, which helps a lot. If I can make it back to Auburn on the way back, then I would be fine. But is this charging enough to do that?
These are complicated questions. I would love to hear from people who have attempted this in the past with EVs and what they recommend about if this is doable or if I should give up and drive my ICE AWD. Clearly the latter would be easier, but I bought the EV to pollute less and that is important to me if I can pull it off.
This is a VERY popular winter driving route in this area. I suspect we will be seeing more and more 60 kWh MSs on the road around here as it is currently the MS population capital of the world so I suspect all these drivers will want to know if this is doable as well. then when the X comes out even more will want to do it.
I very much appreciate any advice or tips or thoughts or opinions. I also very much appreciate the report I can no longer locate but quoted above. Whoever you are, thank you!