ELECTRIC CARS ยท EXPLAINER
The short answer
The EPA range on the window sticker is a standardized comparison figure, not a promise. Expect less in cold weather and at sustained highway speed, and more in mild weather around town. The practical consequence is not that EVs fall short, it is that you should buy for your regular driving with a sensible buffer, rather than paying thousands extra for range you use twice a year.
What the EPA number measures
The EPA figure comes from standardized test cycles run under controlled conditions, with adjustment factors applied. Its purpose is to let you compare two cars on equal terms, and it does that job well.
What it is not is a prediction of your Tuesday. It assumes moderate temperatures, a particular mix of speeds, and no roof box, headwind, or four passengers. Every real-world variable moves you off that number in one direction or the other.
What actually eats range
Cold weather, the big one
Two things happen at once in winter. The battery itself is less efficient when cold, and cabin heat has to come from the battery because there is no waste engine heat to borrow. Winter range losses are substantial and widely reported by owners, and this is the single most common source of “my EV doesn’t get its rated range” frustration.
Two things help a lot. A heat pump is far more efficient than a resistive heater and is worth looking for if you live somewhere cold. And preconditioning while still plugged in warms the cabin and battery using grid power rather than your range, which is one of the genuinely delightful things about owning an EV in winter.
Highway speed
EVs behave the opposite way to gas cars. A combustion engine is inefficient in stop-and-go traffic and happiest cruising. An EV is most efficient in town, where regenerative braking recovers energy and there is no idling, and least efficient at sustained high speed, where aerodynamic drag dominates and rises sharply with velocity.
The practical version: a long highway trip at 75 mph will use noticeably more energy per mile than the same distance of suburban driving. Dropping your cruising speed slightly on a long trip has an outsized effect on range.
Terrain, load, and accessories
Sustained climbing uses energy, though you recover some of it descending through regeneration. Extra passengers and cargo cost you a little. A roof box or bike rack costs you a lot more than people expect, because it wrecks the aerodynamics the car was carefully designed around.
How much range do you actually need?
Here is the reframe that helps most people. If you can charge at home, you begin every day full. You are not managing a fuel tank that slowly empties across the week, you are waking up topped off. Daily range simply stops being a live concern.
So work it out like this:
- Find your longest regular round trip, the one you do weekly or monthly, not the annual holiday drive.
- Add a real-world buffer for winter and highway speed. Assuming you will see meaningfully less than the sticker in bad conditions is the safe planning approach.
- Treat the rare long trip as a charging-stop problem, not a range problem. One 20 to 30 minute fast-charging stop on a long drive is a coffee and a bathroom break, and you were probably stopping anyway.
Buying a much bigger battery to avoid ever stopping means paying more, carrying more weight (which costs efficiency), and using more raw materials, for a convenience you use a handful of times a year.
Battery health over time
Batteries do degrade, but modern EV packs have held up better than early fears suggested, and manufacturers warranty them for long periods with a minimum capacity retention threshold. Habits that help: avoid routinely charging to 100 percent unless you need it for a trip, avoid regularly running the battery very low, and rely mostly on slower home charging rather than constant fast charging. Most manufacturers let you set a daily charge limit for exactly this reason.
What erodes range, roughly in order
Cold weather, by far the biggest factor
Two things happen at once. The battery itself becomes less efficient when cold, and the cabin heater draws real power. Unlike a petrol car, an EV has no waste engine heat to borrow, so warming the cabin costs range directly. In genuinely cold conditions a 20 to 30 percent reduction is normal, and worse on short trips where the car never fully warms.
The mitigation is preconditioning: warming the car while it is still plugged in, so heating comes from the wall rather than the battery. Most EVs do this on a timer or through an app, and it is the single most effective habit in winter. Heated seats and a heated steering wheel also draw far less than cabin air heating.
Speed, and why motorway range is the real number
Aerodynamic drag rises with the square of speed, so the energy needed climbs steeply above about 55 mph. This is the opposite of a petrol car, which is often most efficient at steady motorway speeds. An EV is at its best in town and its worst on a long fast motorway run.
If most of your driving is motorway, judge a car by its motorway consumption figure rather than its combined rating, because that is the number you will live with.
Terrain, load and towing
Hills cost less than people expect, because regenerative braking returns a meaningful share on the way down. Sustained climbing still costs. Load matters less than in a petrol car. Towing is the exception and can cut range by half or more, which is why towing capacity and towing range are quite different questions.
Battery age
Degradation is slower than the early reputation suggested. Most modern packs lose a small percentage in the first year or two and then settle into a slow decline. Manufacturer warranties commonly guarantee around 70 percent capacity at eight years or 100,000 miles, which tells you what they expect.
Why the sticker number is not a lie, exactly
Official range figures come from standardised test cycles, run at moderate temperatures with no heating or air conditioning and a specific driving pattern. They are useful for comparing cars against each other, because every car faces the same test. They are not a promise about your commute in February.
The practical translation: for planning, take the official figure and remove about 20 percent for mixed driving, or about 30 to 40 percent for cold motorway conditions. If the remaining number comfortably covers your regular journeys, the car has enough range.
How much range do you actually need?
Less than most buyers think, and this is where money gets wasted. If you charge at home, you start every day full. The question is not “can it drive 300 miles” but “does it cover my longest normal day, with margin”.
- Work out your longest regular day of driving, not your longest ever.
- Add 30 percent for weather and degradation.
- Add enough that you are not routinely charging below 10 percent, which is unpleasant and slightly harder on the battery.
- Compare that against the car’s realistic figure, not the sticker.
For most households the answer lands well below the biggest battery on offer. The occasional long trip is better solved by a coffee stop at a rapid charger than by carrying an extra 200 kg of battery every day of the year. That extra battery also costs money to buy and carries a manufacturing footprint you rarely use.
Charging speed matters more than range on long trips
On a genuinely long journey, what determines arrival time is not total range but how quickly the car takes charge between about 10 and 80 percent. A car with modest range that charges rapidly often completes a long trip faster than a long-range car that charges slowly.
Look for the peak charging rate in kilowatts and, more usefully, the 10 to 80 percent time. Above 80 percent charging slows sharply on every EV, which is why rapid-charging stops are best kept short and frequent rather than long and full.
Habits that protect long-term range
- Charge to about 80 percent for daily use and save 100 percent for trips where you need it. Most cars let you set this once and forget it.
- Avoid leaving the car at very low charge for long periods, particularly in heat.
- Use rapid chargers when useful, not by default. Regular slow charging at home is gentler.
- Precondition in winter while plugged in.
- Keep tyres properly inflated. Underinflation costs range on any vehicle, and EVs are heavy.
Frequently asked questions
How much range do EVs lose in winter?
Commonly 20 to 30 percent, and more on short trips in severe cold. The battery is less efficient when cold and cabin heating draws power directly, because there is no waste engine heat to use.
Why is my EV range lower than advertised?
Official figures come from standardised tests at moderate temperatures without heating or air conditioning. They are designed to compare cars fairly rather than predict your conditions. Expect roughly 20 percent less in mixed driving and more in cold motorway conditions.
How much EV range do I actually need?
Enough to cover your longest regular day with about 30 percent margin, assuming you charge at home and start each day full. For most households that is far less than the largest battery available.
Does fast charging damage the battery?
Occasional rapid charging is fine and is what the system is designed for. Relying on it exclusively is harder on the pack than regular slower charging at home. Charging to 80 percent for daily use and avoiding long periods at very low charge matter more.
Do EVs use more energy on the motorway?
Yes. Aerodynamic drag rises sharply with speed, so an EV is least efficient at sustained high speeds and most efficient in town. This is the opposite of a petrol car, so judge by the motorway figure if that is your main use.
How fast do EV batteries degrade?
Slower than early reputation suggested. Most packs lose a few percent in the first couple of years then decline slowly. Manufacturer warranties commonly guarantee around 70 percent capacity at eight years or 100,000 miles.