Electric cars are by and large ridiculously fast with pretty poor range, especially the news trucks if they are going truck like things such as towing and hauling. Wouldn’t making them a bit slower increase range and/or reduce battery size and charging time/cost?
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It doesn’t work that way.
The transmission uses whatever mechanical advantage the truck needs for the balance of torque or horsepower depending on the situation.
It basically does both things. Between what you asked if it could do and what it does, it can do both depending on what’s needed.
The only difference is how heavy the battery is for any specific range. More range means heavier batteries.
Yes, decreasing the maximum speed/ acceleration would increase their range. It would also hurt their sales. The speed and acceleration of electric vehicles is a huge selling point.
The additional range can also be achieved by proper driving techniques, just like people can do to slightly improve their fuel economy. But limiting the vehicles artificially would not win people over.
I’ll try to give in easy answer, but this might get a little bit wordy. Sorry I didn’t have time to trim it down.
Yes and no. Electric motors are more powerful horsepower per horsepower than gas cars because the way they deliver their energy is more linear compared to the heavy curves of most gasoline engines.
That being said, a lower powered electric motor does take less energy than a high-powered motor, but running a high-powered motor in a low power doesn’t produce as much waste as a gas motor. Therefore, it’s not less efficient to put a bigger motor in your EV, if you have a mode that restricts the max power usage, you’ll get the benefits of a smaller motor.
As an example, a powerful sports car with an 8 cylinder engine will waste a lot of energy idling and when driving slow. Some newer gas engines can turn off cylinders, turning your 8 cylinder into a 4 cylinder temporarily. But with an EV motor, you just put less electrons through, you don’t need to change anything about the motor itself. Although, some electric cars have multiple motors, and will turn one motor off to be more efficient, so it’s not completely uncomparable.
So we actually know exactly what it looks like to have a less powerful EV motor, and the efficiency isn’t that significantly different. Because electric motors are already so incredibly efficient, You don’t gain significantly more by putting in a smaller motor or having less horsepower.
When driving slow, your electric car will be very efficient. However, the majority of the energy used in driving fast is wasted by wind resistance and tire resistance. No matter how efficient your motor is, if you’re going 70 mph, you will use significantly more energy than going 60 miles an hour, which is quite a bit more than going 50, which is still a bit more than going 40, and under 40 I find it’s all pretty efficient, But Ev’s tend to have peak efficiency in the twenties or ’30s miles per hour.
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However, having less batteries does mean having less weight, and that can make you more efficient overall. And aerodynamics is a significant factor. Most EVs get under four miles per kilowatt hour, but an efficient EV can get up to 5 miles per kilowatt hour. However, the aptera, a teardrop shaped car, can get 10 miles per kilowatt hour, And even has a big battery in one of its configurations.
A truck is generally pretty square by comparison (and tall! Meaning it will have to push even more air out of the way), it’s going to take a lot of energy to cut through the air. They tend to have high friction tires for towing and slip resistance. There’s only so much you can do about efficiency when the truck is shaped and sized like that. They’re always going to get two to three miles per kilowatt hour most of the time (You can max out around 4 I’m sure, but that won’t be how most people drive). The best you could do is have a dual motor configuration that runs in a one motor configuration when you want to be more efficient.
Hope this helps!
Far and away the biggest factor in EV performance at highway speeds comes down to aerodynamics. This is clearly illustrated in the rash of towing testing that various people are now conducting since BEV trucks are now in the market.
Slowing down will absolutely positively impact range, as will choosing a more aerodynamic trailer design.
Reducing the battery size won’t have nearly as much of an effect because the weight penalty is overblown, at least when it comes to highway speeds. It may make a bigger deal if one is generally in stop-start traffic, or with a bunch of hilly terrain.
In fact reducing the size of the battery may actually have a negative effect on overall towing trip times since a larger pack can accept a higher amount of power when recharging for longer. Meaning that you’ll get more kWs faster with a bigger pack. This will be a controversial statement since it will depend on the specific vehicle and how efficient it already is. Definitely not a universal rule but could hold true for some vehicles. But as always, a pig is going to be a pig.
No
A gasoline or diesel engine has efficiency that varies wildly across the range. You get peak efficiency right around peak torque but it falls off as you head higher towards peak power. Punching it and revving up to 5k to get going is going to burn through more fuel to get you up to 70 mph to merge onto the highway than a steady acceleration at 3k rpm. Your engine might be 30% efficient at 3k rpm but only 25% at 5k rpm, while that only looks like 5 percent its really 5 percentage points and a 17% reduction in efficiency.
Electric motors don’t really care. Electric motors can be in excess of 90% efficiency, you may have a bit more or less losses at a specific speed but you’re going to be looking at 85%+ efficiency across the whole range, and when the car comes to a stop the electric motor gets to recoup a large percentage of the kinetic energy
Unfortunately Electric Cars are a basic physics problem. A car with X weight, Y rolling resistance, and Z air resistance requires energy E to move 100 miles at 70 mph. The efficiency of the electric motor only matter a little big, the biggest challenge for the range of electric vehicles is that a gallon of gasoline holds about 15x the energy as a gallon of lithium ion batteries so even if the car is 1/5th as efficient you still need 3x the volume of the best batteries to get the same energy to work with.
Electric motors are efficient across a wide variety of rpms so they usually lack multiple gears and are limited by the energy density of the battery. Sure, if you drive the vehicle slower you will greatly increase your range but that’s at the cost of your time and everyone behind you.
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