Energy Efficiency and Electric Cars: Practical Ways To

Getting the Most Out of Your Electric Car: A Practical Guide to Efficiency

Energy efficiency is super important for electric car owners. It affects how far you can drive, how much it costs, and how often you need to charge. Luckily, you can influence your EV's efficiency more than you might think.

Understanding Efficiency in the EV World

Instead of MPG, EVs are usually rated in miles per kWh, Wh per mile, or kWh per 100 miles. All of these tell you how much energy the car uses to travel a certain distance.

Don't just assume that a big battery means great efficiency. Even with a large battery, an EV can be inefficient if energy is wasted due to wind resistance, tyre problems, driving habits, or cold weather.

Why EVs Usually Beat Petrol Cars on Efficiency

EVs are generally more efficient than petrol cars because they're better at turning stored energy into movement. They also avoid energy waste from idling, engine heat, and transmission friction, which are common in internal combustion engines.

Regenerative braking gives EVs an advantage, especially in cities. When you slow down, the motor acts like a generator, sending energy back to the battery. Even though some energy is lost as heat, regen can really boost efficiency in stop-and-go traffic.

How Energy Is Used While Driving

When you're driving on a flat road at a constant speed, your EV is mainly working against:

1. Wind resistance
2. Rolling resistance from the tyres
3. Energy used by the car's systems (electronics, pumps, lights)

Wind resistance is usually the biggest drain on the motorway, while rolling resistance and frequent acceleration matter more when you're driving around town.

Wind Resistance: The Sneaky Range Thief

Air resistance gets much stronger as you speed up. That's why EVs often seem to use more energy at 75 mph than at 60 mph. Small design details, like a smooth bottom and how air flows around the mirrors and wheels, can make a big difference in efficiency.

Here's what you can do:

• Take off roof racks and cargo boxes when you don't need them.
• Keep your windows up when you're on the motorway.
• Avoid carrying extra gear on the outside of your car unless you have to.

Tyres and Rolling Resistance Explained

When tyres roll, they bend, which turns energy into heat. This energy loss is "rolling resistance." Lower rolling resistance usually means you can drive farther.

Choosing the right tyres is especially important for heavier EVs like SUVs and trucks because their weight increases how much the tyres bend and lose energy.

Tyre Tips:

• Keep your tyres properly inflated, and check them when they're cold.
• Don't use different tyres on the same axle.
• Pick tyres that fit your driving needs, not just the cheapest ones.
• Rotate your tyres regularly to prevent uneven wear, which increases drag.

Underinflated tyres can quickly reduce your range by increasing bending and heat. Low pressure also wears out tyres faster, so fix pressure issues before you think about other upgrades.

Driving Style: An Easy Way to Improve Efficiency

EVs have a lot of torque right away, which can be fun, but quick acceleration uses a lot of energy. Driving efficiently isn't about going slow; it's about being smooth.

Try these techniques:

• Speed up gently and steadily.
• Look ahead and let off the accelerator early instead of slamming on the brakes.
• Use regenerative braking to slow down whenever you can.
• Use cruise control on long motorway drives, but keep your speed reasonable.

Speed is a big deal. The faster you go, the more wind resistance affects your battery.

How Climate and Temperature Affect Efficiency

Cold weather can reduce EV range for two main reasons:

1. Batteries work best when they're warm.
2. Heating the cabin can use a lot of power.

EVs with heat pumps are generally more efficient in the cold than those with regular heating, but all EVs lose some range in the winter.

Here's how to deal with it:

• Preheat the cabin while the car is plugged in.
• Use seat and steering wheel warmers instead of just turning up the cabin heat.
• Park in a garage if you can.
• Plan to charge more often in the winter.

Air conditioning in hot weather also uses energy, but heating in the winter often has a bigger impact on range.

Charging Losses: What You Should Know

Not all the electricity from the wall makes it into the battery. Some is lost as heat, during conversion, and by the battery management system. Fast charging can create more heat and energy loss than charging slowly at home, although it's faster.

To charge more efficien