Last time we checked in, we had 160 miles of rated range and Barstow was a mere 150 miles away.
Leg 1: San Diego to Barst… ABORT! San Juan Capistrano
Time of day: Night
External temp: Low 70s.
Winds: Still minimal (3-5 mph)
Driving Speed: Initially 70 mph +/- 5 mph. I used cruise control whenever possible. As the rated ranged dropped quicker than the actual range, I decreased the speed. I never got it down to 55 though, as that speed just seems unsafe when everyone around you is going 75+.
Climate Control: Set between 72-74 F The heat actually came on for a little bit, so we turned on the seat warmers.
Roads/Traffic: Minimal traffic on this stretch, which is part of why we left so late in the day.
Notes: Well, we needed more of a charge before attempting this leg. If the level 2 charger was functional where we ate dinner we might have been okay. I was keeping one eye on the rated range and the other on the actual distance to Barstow (and a third one on the road). It became evident by the time we we less than halfway there it wouldn’t be enough. So I was faced with the choice of changing course and heading to San Juan Capistrano and using the Supercharger there or finding a level 2 charger along the way and hoping that it was functional and that it would provide a quick enough charge that we wouldn’t be sitting there all nigh trying to get an extra 50 miles. I chose the Supercharger route based off my experience with the level 2s in San Diego. Admittedly it was a small sample size, but of the 3 I tried 1 didn’t work and the other 2 only provided 15 miles per hour of charging. I turned off on Highway 74 by Lake Elsinore and holy cow, that is one ridiculous road. It’s about 30 miles of twisting mountain road. Oh, and there are no lights.
We arrived at the SJC supercharger with about 40 rated miles left. We started with 160 and only traveled 90. I forgot to record the kWh used for this segment, but I’m sure it was fairly high and I don’t plan on repeating this route again. We plugged in and shortly were up to 175 rated miles. That should be enough as Barstow was only 120 away. Right?
Leg 2: San Juan Capistrano to Barstow
Basically the same as Leg 1, but later.
Roads/Traffic: Construction? Oh come on. The section of I-15 North just oust side of Ontario was down to one lane for construction. We probably averaged about 3 mph. If we had left earlier in the day we would have missed it since it didn’t start until after 9 pm. So much for my plan of traveling at night to avoid traffic. As we crept along, I watch the rated range keep going down while we made very little actual progress. We should have had a 55 mile cushion for this leg and pulled into Barstow with only 20 left.
Legs 1 & 2:
Distance: 212 mi (Rancho Bernardo to Barstow via Hwy 74 & San Juan Capistrano )
Energy used: 67.9 kWh, average 320 Wh/mi
It’s hard to take much away from this given the change of course and the road construction. However there is one thing I’ll keep in mind for future trips. The elevation change from Rancho Bernardo to barstow is almost 2,000 feet. That change includes a cumulative elevation gain of 14,300 feet plus 12,406 feet of descent. That more than anything else likely caused the discrepancy between our rated and actual range. So how much of a charge would I need in the future to go straight from Rancho Bernardo to Barstow. We averaged 320 Wh/mi for the weird combo of legs and construction, so if I multiple the 150 miles by 320 Wh/mi then we would need 48 kWh. The Tesla doesn’t have a kWh gauge but if you look at the energy screen you can get an idea:
If you multiple the Wh/mi by the average projected range you can get an estimate of the kWh remaining in your batter. In the above case I would estimate we have 69 kWh remaining of our 86 kWh battery. I don’t know how precise that is, but I bet it’s gotta be close. I’m going to test it out around town and on our next trip whenever that may be.
So with the construction we arrived in Barstow at about 2 am. At least the supercharger was empty. I decided to throw in the towel and checked us in to the Country Inn right next to it. They had unfilled rooms and given that they were unlikely to book them between 2 am and checkout they gave me a discount rate. The room had 3 queen beds which meant I got to sleep without a kid’s foot in my back for the first time on the trip.
On the way back from Barstow to Las Vegas we used 56.2 kWh averaging 311 Wh/mi. This is up from 54kWh and 301 Wh/mi going the other direction. The conditions were about the same but I drove a little faster so I think that accounts for the difference.
For the whole trip we traveled 934.5 miles, used 293.7 kWh, and averaged 314 Wh/mi. I’ll probably skip San Juan Capistrano in the future as it shouldn’t be any problem to travel between San Diego from Barstow as long as the battery is 2/3 full (especially for the return trip). It is nice that the SJC supercharger is there just in case, and this all might be moot in a year or so as Tesla continues to expand its Supercharger network. One in Riverside would make the Barstow to San Diego leg a piece of cake.