Energy Efficiency and Electric Cars: Practical Ways to
I drove from Boston to New York last October in a friend's EV. He'd been complaining about range anxiety for months. Turned out his tires were 12 psi underinflated and he'd been cruising at 78 mph the whole time. We dropped to 65, pumped the tires at a rest stop, and made it with 40 miles to spare.
No new battery. No software update. Just two small adjustments.
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What efficiency actually means
With a gas car you track MPG. With an EV the number is miles per kWh — same idea, different unit. A bigger battery doesn't automatically mean better efficiency. A heavy SUV with a massive pack can still drain faster than a lighter sedan if the driver floors it on the highway with a roof rack attached.
Three things eat range on a flat road at steady speed: aerodynamic drag, tire rolling resistance, and accessory loads — heat, AC, lights, electronics. At highway speeds, aero drag dominates. In city traffic, acceleration and rolling resistance matter more.
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Tires: the thing most people ignore
Tires flex as they roll. That flex generates heat. Heat is wasted energy. Underinflation by 10 psi costs 5 to 10% more energy on the highway. For a 300-mile vehicle, correct cold tire pressure alone can recover 9 to 15 miles per charge. Check it every two weeks.
For heavier vehicles — electric vans, SUVs, trucks — this compounds. More weight means more tire deformation, more rolling resistance, more drain. Commercial operators running 20,000 miles a year can save $300 to $600 annually per vehicle by switching to lower rolling resistance steer tires designed for this purpose.
Rotate on schedule. Mismatched wear across an axle adds drag.
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Aerodynamics: the quiet thief
Air resistance increases with the square of speed. Going from 65 to 75 mph costs 15 to 20% more energy over a long trip.
Roof racks and cargo boxes make it worse. A ski box at 70 mph creates significant drag even when empty. Take it off when you don't need it. Keep windows up on the highway.
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Driving style: the biggest lever you have
Hard launches feel satisfying but cost energy. Efficient driving isn't slow driving — it's smooth driving.
Look further ahead. Lift off the accelerator early instead of braking late. Let regenerative braking do the work. On the highway, set cruise control and keep it at a reasonable speed.
When I drove that Boston–New York trip, slowing down from 78 to 65 added nearly 40 miles of range. Same car. Same road. Different foot pressure.
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Winter: plan for it
Cold batteries underperform. Cabin heating draws significant power — more than AC in summer for most EVs.
Precondition the cabin while still plugged in. Use seat heaters and steering wheel heat instead of blasting the full cabin. Park in a garage when you can. Plan for more charging stops on cold-weather trips.
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Charging: the part nobody talks about
Not every kWh from the wall reaches the battery. Heat, conversion losses, and battery management take a cut — typically 10 to 15%. Fast charging adds more loss than slower home charging.
Charge at home when possible. Avoid charging to 100% daily unless the trip requires it. If your utility offers time-of-use rates, scheduled overnight charging cuts costs noticeably.
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For fleets: treat efficiency as a process
Track energy use by vehicle and route. Standardize tire pressure checks. Train drivers on smooth acceleration and early regen. A fleet van at 20,000 miles per year with optimized tires and trained drivers runs measurably cheaper than the same van operated carelessly.
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This week's checklist
Check tire pressure cold. Remove any roof gear you're not using. Precondition the cabin while plugged in. Drive smoother, lift earlier. Drop highway speed a little. Use seat heaters instead of max cabin heat.
None of these require spending money. They just require paying attention.
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FAQ
How much range does correct tire pressure actually add? Around 3 to 5% for most EVs. On a 300-mile vehicle that's 9 to 15 miles per charge. Check cold pressure every two weeks, especially before long trips.
Does driving style matter more on road trips or daily commutes? Both, but differently. On the highway, dropping from 75 to 65 mph can save 15 to 20% over 500 km. In city driving, smooth acceleration and active regen can improve efficiency by 10 to 25%.
Are low rolling resistance tires worth it for electric trucks and vans? Yes. Quality steer tires can reduce energy consumption by 4 to 8%. At 20,000 miles per year and $0.15 per kWh, that's $300 to $600 saved annually per vehicle.
