When trying to figure out how much range you might need in an EV, it's important to consider all of the factors that could impact your range on a daily basis. Most of these factors are ALSO true for gasoline vehicles, but most of us aren't even aware of how many miles our gasoline-powered cars can travel on a single tank (and even fewer of us notice when that number fluctuates). Since we all know there will be a gas station where and when we need one, it's never been that important to pay attention to these things.
In an EV, charging takes longer than getting gas and charging stations are not yet ubiquitous like gas stations. That makes the amount of range you have important. An EV's advertised range is an estimate, based on a set of average conditions in simulated testing. There are all kinds of factors that can impact how much range you may have available. Let's review them, so you can better anticipate your needs.
Cold temperatures can reduce your range by more than 50%.
If you live in a harsh climate, you should know that cold temps can significantly reduce your available range. This is due primarily to two factors:
EV batteries are a bit like people, in that they're not very happy when they're cold. A cold battery will be less efficient than a warm battery, so you can expect some range loss while the battery comes up to temperature. The good news is, if the car is plugged in you can avoid this cold-weather inefficiency by warming the battery (and passenger cabin at the same time) before you drive. This is called "Preconditioning". Think of it like a remote starter, but instead of just warming the cabin for you, it's also warming the battery at the same time. Some EVs will even allow you to set a recurring schedule for preconditioning, so the car warms the battery in anticipation of your morning commute each day.
Your car's climate control is the single most power-intensive feature it has. Running the heater (or air conditioning) will draw a significant amount of power and can reduce your range accordingly. Heated seats are more efficient than your car's heater, so many energy-conscious EV drivers will use heated seats to stay warm before resorting to the climate control.
Filling your car with more people and stuff can weigh it down, and a heavier car takes more energy to move. This can have a meaningful impact on range, how much really depends on how much weight you're adding on any given trip.
Disrupting your car's carefully designed aerodynamics can reduce range as well. This is most commonly done with exterior accessories like roof-top tents, roof racks for kayaks, skis, bikes, etc., or things like exterior-mounted off-road lighting. Be aware that mounting these types of accessories will come at the cost of range reduction. How much range reduction again depends on the amount of aerodynamic disruption - but here is some food for thought: Car and Driver tested a Tesla with and without its aerodynamic wheel covers, and found that even this small difference was worth about 10 miles of range. That's not insignificant!
This one is simple, it takes more energy to drive uphill than it does to drive on flat ground. The car can use regenerative braking to recapture some energy on the way back down a hill, but the round trip will typically be less efficient than driving on a flat road. If you live in a mountainous area, expect that you'll chew up your range faster than average.
In a gas car, highway driving is typically MORE fuel efficient than city driving. The opposite is true in an EV. That’s because in city driving, each time you slow to a stop the car can recapture some energy. On the highway, there are far fewer opportunities to recapture any energy, and you’re using quite a bit to maintain that highway speed against higher wind resistance - especially if traveling over 70mph.
Your car will be slightly less efficient while driving in rain and snow, and the same can be true if driving into a headwind.
EVs often come with tires designed for efficiency. These may be a different rubber compound than the tires on similar gasoline cars. Putting the wrong tires on your car (or cheaper tires not designed with efficiency in mind) could negatively impact your range. Also be sure to keep those tires properly inflated, as low tire pressure can be a drag on your efficiency as well.
This one should be obvious. If you have a lead foot and punch it between stoplights at every opportunity, the car will be less efficient than if you were driving delicately around town.
Batteries lose some of their capacity over time. Most automakers include some protection around degradation in their warranty, which is definitely a question you'll want to ask when choosing your EV. Degradation can happen for a number of reasons, which we’ll address in a different article.
As you can probably tell by now, there are too many factors at play to be absolutely certain about how much range you'll actually need; but knowing all of the various factors that could affect you will help you approximate your needs better, and help you make a better overall choice that is more likely to work for you.