- (+) The vehicle chosen was a Model 3 LR RWD Aero, an excellent road-tripping EV.
- (-) Upgrades to 145kW, in progress, were not considered for the (currently 120kW) V2 Superchargers, and the V3 rollout is only scheduled to begin en masse later this summer/fall.
- (-) ABRP uses relatively conservative assumptions about energy consumption
- (-) ABRP is extremely aggressive about keeping you off of highways when you tell it to avoid them; it'll prefer to let you almost run out of electricity or slow way, way down than spend even a moment driving on a highway.
- (*) The routes were picked randomly within a simple bounding box across the continental United States. Some routes had to be discarded due to being impossible (such as being out to sea).
- (-) While people frequently visit or pass through remote areas, road trips are most often done in areas where more people live (as can be seen in road traffic figures), which also tend to have a higher density of chargers. The software is however quite likely to pick trips out in the middle of bloody nowhere.
- (*) Vehicles were chosen with a variety of ages (degradation modeled on that of the Model S, although it should be if anything lower for the 3), payload weights, road conditions, and winds (both headwinds and tailwinds).
- (*) ABRP was instructed to not let the charge level drop below 10%.
- (*) Stock ABRP values were used for everything not specified above, including 3 minutes of overhead (similar to gas station overhead) for every stop. This time is subtracted from the length of a stay, since it's not time you actually spend at a given location.
- (-) While in the real world, people road trip most during times of year when there's good weather, and often delay trips when there's bad weather, no attempt was made to emulate this; the vehicles are simulated in sometimes extremely hostile conditions.
- (-) Tires become more efficient as they wear down. No attempt was made to account for this.
- (+) For third-party chargers, the CHAdeMO adapter may not yield as high speeds as native CCS support; a CCS adapter is coming but not yet available (European Model 3s support CCS natively). This may yield higher speeds at US third-party stations than would actually be achieved. Regardless, usage of third-party stations was relatively rare, and omitting or slowing them did not make a significant difference to the results.
- (-) Some trips were long enough that they would almost certainly be done with an overnight stay. This was not modeled. An overnight stay with charging equates to the removal of a long charging stop and part of a subsequent stop (as one charges to full overnight, unlike during a midday stop)
Notice that the average time between stops is surprisingly long – similar to, if not longer than, most people generally take between stops during trips in gasoline cars (one can of course take more frequent stops if they choose). Stopping is thus not an imposition, but a requirement of your need to refresh your bladder, your legs, your stomach and your mind. Part of the reason for the long time between stops is that backroads generally have lower average speeds than major highways; this not only means that it takes longer to travel a given distance, but additionally, EVs become more efficient at lower speeds.
As for the length of the charging stops during the various trips and the percentage of the trip spent charging:
To see how much of a difference the upcoming V3 standard makes, here's a 2017 Model 3 charging on a V3 charger:
5% – 16 miles – 1 min (250 kW)
20% – 62 miles – 4 mins (250 kW)
21% – 65 miles – 4.5 mins (Taper from peak starts – 248 kW)
30% – 92 miles – 6 mins (218 kW)
40% – 123 miles – 8.5 mins (179 kW)
50% – 153 miles – 11 mins (142 kW)
60% – 184 miles – 14.5 mins (108 kW)
70% – 213 miles – 19 mins (87 kW)
80% – 245 miles – 24.5 mins (56 kW)
90% – 275 miles – 34 mins (36 kW)
Additionally, there were two cases where ABRP reported a nominal “slowdown”, yet the speed they reported was basically the same speed that Google reports as normal for said route. Consequently, these – while “redlined” – should probably not be considered slowdowns.
This honestly should not be unfamiliar to people driving gasoline cars in remote areas.
In every single other case – regardless of how awful the driving conditions were or where the trip was – there was neither red-lining slowdowns nor any backtracking detours at all. All remaining valid cases follow (read: prepare to scroll down! Summary follows)
- Excepting the “North Dakota Hole“, which will surely be closed very early in the lifespan of any EV purchased today, a “good road tripping EV” can easily manage backwoods trips between arbitrary points in the continental United States – regardless of the road and weather conditions, payload, and even accounting for battery degradation in older vehicles. In rare cases one might need to take a leg or two on a highway, but these are edge cases, and far from the general rule.
- It's almost impossible to drive for long distances without crossing a major highway unless you're driving in circles.
- EVs frequently travel further on backroads than they do on highways, with less frequent stops required.
- Electrify America really needs to lower their prices. The stark difference between Supercharger and Electrify America pricing really stood out in this comparison.
- Extreme-cold temperatures, and particularly gale-force headwinds, will ruin your energy consumption – but even that had little impact on the overall ability of EVs to make comfortable road trips on backwoods roads with today's infrastructure – let alone tomorrow's.