How does somebody win a rally like this? It’s not like there are lots of other electric vehicle rallies to compare to, particularly those with a distance of 1500 miles (2400km) to cover. The first thing to consider is that electric vehicles have a wide range of performance between models. In most rallies, the fastest car with the best driver(s) would be the only ones with a hope of winning.
The overall score in this rally is determined by a combination of the lowest time (however that time cannot exceed a 70mph / 113kmh average speed for the course) and the best poker hand derived from playing cards collected at checkpoints during the rally.
Obviously, not getting any of the playing cards would make even the fastest car not likely to win. Therefore, the drivers have to consider how much time they will sacrifice, and how many extra miles they will drive, to collect each card. Will five cards be enough? Perhaps, if those five cards represent a really, really good poker hand.
At some point, the fastest cars have to gamble that they have enough cards, and concentrate on completing the course promptly. The slower cars need to gamble that the only chance they have to win is to gather a lot of cards.
Speed isn’t every thing with electric cars, because the fastest car doesn’t necessarily have any particular advantage over the slowest car. Most importantly, the advantage will typically go to the car that can recharge the fastest.
If electric car A takes 7 hours to recharge and can then travel for 2 hours at 50 miles (80km) per hour, then the total distance traveled in 9 hours will be 100 miles (160km), or about 11.1 miles (17.8km) per hour average.
If that same car A were slowed to 25 mph (40km/h), and that speed could produce 150 miles over 6 hours, now the total time is the same 7 hours charging, plus 6 hours traveling for a grand total of 13 hours for 150 miles (240km), or 11.5 miles (18.5km) per hour average.
So, as you can see, there is not much gain in average miles gained per hour elapsed with both examples of significantly different speeds, with the 11 mph average in both of the above examples. But, there are 4 hours lost at the slower speed. Advantage goes to the higher speed. Now, lets double the recharge rate of car A.
The driver in the double speed recharging car B can cover 100 miles at 50mph in 5.5 hours, or 18.2 miles (29.3km) per hour average. That’s a gigantic uptick in overall speed. Again, slowing the car to 25 mph means that the totals are 10.5 hours for 150 miles, or 14.3 miles (23km) per hour average.
As we can see, speed over the ground is trumped by charging speed for the overall fastest average speed between car A and B in our examples. The gap widens as the charge rate increases.
Now, let’s throw in really fast chargers, “DC chargers”, that can recharge car C in 1 hour. Now that 50mph drive can cover 100 miles in 3 total hours, or 33.3 miles (53.6km) per hour. That is nearly double the average speed of the car. If we slow to 25mph, and once again get 150 miles of range in doing so, then we can travel that distance in 7 total hours at 21.4mph (34.4km/h) average speed. Again, the gap continues to get larger between faster speeds and slower speeds, favoring faster speed with the faster charge rates.
But, there will be times when it’s necessary to reduce speed because the next charging station may be too far away to reach at a faster speed. Every situation will require careful considerations as to what speed is best, from the fastest car to the slowest one, but there’s little question that the fastest car with the fastest charge speed will make those considerations much easier! Unfortunately, for those fastest cars with the longest range (Tesla Model S), there isn’t a single operational “really fast” DC charger along our course for them to use on this year’s course.
That will be entirely different next year for the Tesla Model S and maybe the Model X cars, as Tesla will have many new mega-fast DC “Superchargers” along this route by then. These will add to the growing “CHAdeMO” fast DC chargers that are currently along the West Coast Electric Highway in the Pacific Norwest USA and Pacific Southwest Canada, and used in cars like the Nissan LEAF (best selling electric car in the world, ever!) and the Mitsubishi iMiev. Cars without any DC charge port are at a severe disadvantage in this event, but the Tesla Roadster and Toyota Rav4 EV Gen II will make respectable times with big batteries and equally big “onboard” AC chargers.
The overall winner of this year’s rally will get a really nice trophy and some serious bragging rights. In addition, the top finisher Tesla Model S team will get a beautiful new Teslaccessories “Center Console Insert” (an $865 value), so I expect fun, but focused rally driving!
We’ll see you out on the road.