by Timothy Lutts
There’s an interesting sign on the Route 90 in Massachusetts (also known as the Massachusetts Turnpike or Mass Pike).
The sign has been there a long time, and until recently, it was nothing more than an intellectual curiosity. But then I got my Tesla Model S, which runs solely on battery power. And after a few weeks of ownership, I took a 250-mile road trip, out the Mass Pike, around Albany, New York, and up to Lake George.
I’ve already written about how the Tesla delivers an unparalleled driving experience, thanks to its ability to deliver as much power as the driver wants, instantaneously and quietly. But this road trip would test the limits of the Tesla’s rated 265-mile range. And I was a bit worried about getting over those hills—because going uphill takes more power. Happily, going downhill uses less, and in the Tesla, going downhill actually puts energy back into the battery!
That 265-mile range was the government’s number, and as we all know, most drivers fail to equal the government numbers, especially if they like to drive 80 mph, like me.
Fortunately, Tesla’s web site includes an excellent user forum with every topic of interest to owners of these revolutionary cars, and the topic of long-distance driving has been covered at length.
The main pieces of advice are these. Make sure tires are properly inflated—something I always do anyway, charge battery fully (otherwise, it’s best to charge the Tesla to 80% of capacity to prolong battery life), and go slow, using cruise control when possible. Finally, start the journey at a relatively slow speed and monitor battery status along the way; you can always finish at a faster pace if the battery has power to spare.
So that’s what I did, monitoring distance to destination, “rated range” of the battery (based on Fed numbers), “projected range” of the battery (based on the past 30 miles of driving), kWh used for the entire trip, and Wh/mile. This is a great car for people who love numbers!
Also, I had located a few places on the route where I could stop and recharge if necessary. And after 200 miles, just north of Albany, I did stop for an hour in Clifton Park, New York to charge for an hour at Kohl’s—for free.
Which brings me to the pleasant tale of ChargePoint, the world’s largest provider of electric charging stations—there are now more than 13,000, including eight in City of Salem public garages. ChargePoint doesn’t make the charging stations, but it does market them to property owners (typically, cities, hotels, restaurants, stores and universities) and it operates the network that makes the system work. And the cool thing is that the property owners choose what to charge their users, and it’s typically nothing! So for an hour in Clifton Park, I took a walk, bought a newspaper and did the Thursday New York Times crossword puzzle while adding 18 miles of range to the Tesla.
In the end, I didn’t need that charge, but I wasn’t 100% certain that I’d find a charge in Lake George, and as there were no other chargers up there but the one I was aiming for at the Holiday Inn, the Clifton Park charge was a bit of insurance. Happily, the Holiday Inn charger was all I expected, and it was free, too.
Bottom line, the trip out was 250 miles, I used 68.8 kWh of electricity, at 267 Wh/mile.
Coming home three days later, I did the trip non-stop (knowing my garage charger was at the end), and the final tally was 247 miles, using 66.3 kWh, at 267 Wh/mile.
And going over that peak on the Mass Pike was a piece of cake.
In fact, one of the ongoing discussions on the Tesla forums is about the most efficient way to handle the downhill segment of such hills—whether it’s best to stay in cruise control at say, 70, and let gravity recharge the battery (at perhaps 70% efficiency) or let the car pick up speed (to as high a speed as is comfortable—maybe 85?) before engaging regeneration.
There’s no easy answer; it’s one of the intellectually fun aspects of the car.