Because the two energy drains swap places. At highway speed, most of an EV’s energy goes into pushing air aside, and air resistance climbs steeply as speed rises. In town, speeds are low, drag is small, and every stop hands some energy back through regenerative braking. A petrol car shows the opposite pattern: it wastes fuel idling and running at low load in town, then settles into an efficient highway cruise.
Key Takeaways
- Air resistance rises steeply with speed, so highway cruising is an EV’s most expensive driving.
- Town driving is cheap for an EV: low drag, no idling, and regenerative braking refunds part of every stop.
- Petrol cars show the mirror image — worst in town, best at a steady cruise.
- Rated range blends both patterns; your city-highway split decides which end you experience.
Air Resistance Sets the Highway Bill
Rolling resistance changes little with speed. Air resistance does not play along: it grows much faster than speed does, roughly with the square of it, so doubling your pace multiplies the air’s pushback several times over. At town speeds that pushback is a minor line in the energy budget. At a sustained fast cruise it becomes the largest one, and the battery pays it continuously, mile after mile, with no stops to recover anything in. That is why a highway leg drains a charge far faster than the same distance across town.
In Town, Stops Give Some Energy Back
City driving is a chain of accelerations and stops — wasteful in a petrol car, partly refunded in an EV. Each time you slow down, regenerative braking turns part of the car’s motion back into charge instead of brake heat, as whether an EV can charge while driving explains. The motor also draws nothing while you wait at a light — there is no engine idling — and at low speeds it works in an easy, efficient range. None of this makes town driving free, but the recoveries stack up against a small bill.
Why Petrol Cars Lean the Other Way
| City driving | Highway driving | |
|---|---|---|
| Electric car | Low drag plus energy recovered at every stop — most miles per charge | Air resistance dominates the whole way — fewest miles per charge |
| Petrol car | Idling and low-load running waste fuel — worst economy | Steady cruise suits the engine and gearing — best economy |
An engine is least efficient doing gentle, interrupted work, and it burns fuel at every red light while travelling nowhere. Its gearing suits the steady state it reaches on the highway. The EV has the reverse profile: nothing to idle, energy back at every stop, and an air bill that only grows serious with speed.
What This Means for the Range on the Sticker
Official range figures blend both worlds: the test cycles mix city and highway driving, and FuelEconomy.gov publishes separate city and highway ratings as well. Your own split decides which end of the blend you live at. Three practical consequences follow:
- Judge your car by your week. A town-heavy week will show more miles per charge than the sticker suggests; a highway-heavy week will show fewer — from exactly the same battery.
- Plan trips around the highway legs. They are the expensive miles. Treat them, not total distance, as the planning constraint, and leave margin for weather — cold squeezes both patterns, as cold-weather EV charging describes.
- Town range is easy to replace at home. Level 2 charging adds roughly 10 to 20 miles of range per hour (U.S. DOT typical figures), so an evening on a home charger covers days of city driving.
That overnight top-up is what a wall charger such as the EVDANCE EV-ACT5006T 48A Level 2 wall charger or a portable unit like the EVDANCE EV-ACS3210T 32A portable charger is built for: plug in after the town miles, wake to a full working range.
Frequently Asked Questions
Is the rated range a city figure or a highway figure?
Neither — it is a blend of both test cycles. Where separate city and highway ratings are published for your model, compare them against the driving you actually do; the combined figure sits between them and suits a mixed week better than either extreme.
My range fell sharply on a long highway trip. Is the battery degrading?
Almost certainly not. Sustained speed is the likeliest explanation — the air bill, not lost capacity. Compare full-charge range on similar routes in similar weather before suspecting the battery, and use how to check EV battery health if it persists in normal driving.
Does a roof box matter more in town or on the highway?
On the highway, by a wide margin. Extra drag is the highway’s main cost, so anything that enlarges the car’s shape taxes fast cruising far more than slow town trips, where the air bill is small.
Related Reading
- Can You Charge an EV While Driving?
- How to Check EV Battery Health
- Cold-Weather EV Charging: What Happens to Chargers and Cables Below Freezing
- How Much Does It Cost to Charge an Electric Car at Home?
