EPA mileage estimates are sort of bizarre. In EVs, once the range is 200+ miles, the more important factor is probably speed of fast recharging and availability of DC fast charging networks.
But looking at the “range” value is probably what most consumers focus on when making decisions. Tesla has mastered the “Adjustment factors” to get higher EPA ratings.
Source: The Adjustment Factor Tesla Uses to Get Its Big EPA Range Numbers
I used an online tool to calculate charging options for several EVs traveling over a specific route. One model, we will call Model 1, required 3 stops for 30 minutes each, plus one stop for about 45 minutes, to reach the destination. It’s maximum charging rate is about 50 kwh. That’s just over 2 hours of charging time.
One of the other cars is the Tesla Model 3 – which has access to high current DC fast charging stations along the route at up to 150 kwh.
Clearly, the Model 3 can be re-charged at a much faster rate than the “Model 1”.
In fact, the Model 3 required about three 10-12 minutes DCFS stops at 150 kwh stations, followed by one 25 minute charge near the end.
“Model 1” had over 2 hours of charging time on the route while the Model 3 had just under one hour.
The ability of the vehicle to accept the truly high powered chargers – and the availability of fast charging networks at high current makes a big difference.
Another factor is EVs do their fastest charging in sort of the bottom half of the battery capacity. Once the charge cycle refills past 50-60%, the charge rate starts to drop. It takes longer – a lot longer – to charge up the last 20% than it did to charge from 20-40%!
This means you’ll recharge to 70%, drive down to 20%, recharge back to 70% – and so on, to minimize charge time. But that is only possible if DC fast chargers are located in the right places along your route.
Battery capacity, the charging rate and charge curve, and availability of fast charging stations – all factor into your ability to drive long distances in a given amount of time.
I’ve concluded a charge rate of at least 75 kwh is going to be an important feature to make EVs practical for my sort of long distance travel here in the west where distances can be quite long. The vehicles charging rate, the charging curve, and your availability of fast chargers should all be considered when evaluating EVs.