if you accelerate quickly, even if your maximum speed is the same, you ARE driving faster on average. You spend more time at the higher speed.
I fairly often get 3.1, when I drive like a grandmother on ludes. But it's all over the place: 1.9 through 3.1 if not towing. Towing 1.0. I live where it is very very flat, and fairly temperate.
I missed this one back in July. Hopefully my reply will pop it back near the top for some people. It's an interesting view about acceleration heat losses.
.I don't believe acceleration is as big a factor as you seem to think it is. Is it a factor? Absolutely. But as an example, take a hard acceleration from 0-70, the power draw is extremely high, iirc something like 170kw but when you release the pedal the inertia of the truck regens some of it. Most of your total pack usage difference is going to come from the fact you are driving faster for a longer period of time. As far as the small accelerations in driver input, you aren't factoring in the deceleration power savings. As far as hills are concerned, I would argue that going downhill regens back to the pack, but I would guesstimate that it's only about 80% efficient. I'm going to assume a spherical cow with 200 mi normal range with perfect 50/50 up and down slopes and 80% regen efficiency.I missed this one back in July. Hopefully my reply will pop it back near the top for some people. It's an interesting view about acceleration heat losses.
This has to be balanced with what the heat losses are in the first place relative to total energy usage. Most energy (~90%) goes into rolling and wind drag. So, if 10% goes into overall battery and motor losses and you accelerate rapidly a few times on a trip, it's probably not going to affect range more than a percent or two, unless you're having a LOT of fun! Accelerating for 5 seconds from 0 to 60 might quadruple the current (from a normal acceleration (I haven't checked it)) resulting in a 16x increase in heat energy but it's only for 5 seconds.
But it underlines the advantages of using cruise control. Most drivers are not as good at speed control as they think. We've all been with drivers who are constantly +/- 10 and who think they're driving fine and won't take the hint to use cruise (while you're looking for the Gravol). Anyone of us might be one of them
All those little accelerations create a little bit of extra heat loss. This even applies if you're using adaptive cruise and you're behind someone who can't control their speed well. Either pass them, or back off and set your cruise to their average speed.
I would think that a few hundred small driver-induced accelerations per hour would exceed the effect of a few single rapid accelerations. If you're in the city and accelerating hard a lot, it would definitely make a difference but you're probably not going to do 250 miles and will be home to charge that night. So, it would affect the numbers but not really a range issue.
We've all seen that going up hills even at steady speed also causes high burn similar to acceleration so hilly drives kill range too. A lot of little hills adds up. Going uphill at high speed requires even higher current. So, slower in hilly country would be better.
Slightly off topic... I think that using cruise on a longer road trip balances the best arrival time with the least opportunity to get a speeding ticket as well as maximizing range. Set the speed just below the max speed you you think you're going to get away with. If you're targeting this speed with your foot, you might be over a bored cop's limit just at the wrong time and you will be under it for at least some of the time. If you're on a 10 hr road trip targeting a max of 75 by foot you'll probably average a couple below 75, it will take an extra 20 minutes on that trip and you won't get the burn benefit of averaging slightly slower because you're constantly changing speed. This is especially true in an EV with no engine drone to give us a speed clue.
One thing that wasn't clear in HOTAS' post with reference to speed is that it's AIRSPEED that's the range killer, not just speedometer speed, especially in our bricks. And airspeed often applies to your whole day's trip. A 20 mph headwind while driving at 55 reduces range by 30%, the same amount as if you drive 75. Either can knock 100 miles off your range with a full charge. Cold temps can reduce your available kWhs to 80% or less. If you only charge to 80% in these temps, then lose 30% to the wind, a 320 mi (510 km) range can drop to 145 miles (220 km). The truck knows the SOC and the temp before you leave but not the wind, so the GOM will show you ~200 mi (320 km). If your destination is 150 miles into a 20 mph headwind, you gradually go from a 50 mile buffer to not getting there. Hopefully you'll notice before the last charge station.
This is going to be a problem in the future for those who won't understand the impact of wind or speed. Current EV owners are keen and, even then, some don't fully understand their vehicle efficiency. In the future there will be a lot of owners jumping in who just want to get in and drive.
Yup, figured you were in the WARM BELT, I'll post my 100% snap shot Sunday evening I expect a less optimistic GOM value for a New England Winter day.
Iām at 2.7 miles per kilowatt hour after 24,100 miles. I donāt drive it like I stole it and I use the heated seats and steering wheel in the winter. In the Summer, the AC is set to 80 degrees
And don't drive on highway at speed limit...
54 psi in your tires!Hereās a screenshot of mine from Sunday morning when I charged it to 100% for the first time in a while just for the hell of it.
Driven about 80% local, 20% hwy.
When on the highway Iām 75-85mph, and when local itās fairly conservative because local police have no crime to deal with around here and are looking for something to do.
The steering wheel and seat heaters are always on, but the HVAC isnāt doing much this time of year in FL, itās gorgeous outside!
The front always has a few hundred pounds of tools in it so the rake is more drastic than normal and looks kind of stupid to be honest, but perhaps that factors into hwy range.
That's one way to get better efficiency.54 psi in your tires!
