Max speed - 90mph?

[GaRailroader]

I had kind of figured out this concept while I was learning how to estimate my bicycle speed without a speedometer.

This video is a great illustration. Actually makes me want to try to build a real seconds-per-mile speedometer.

This illustration is probably even more pronounced in a low range EV like the Slate. They should make a secondary speedometer that shows kWh consumed per hour at that speed. On a longer road trip drivers would learn that they may save time by driving 65 mph instead of 75 mph because they eliminate a charging stop.

 

[ClayJar]

On a longer road trip drivers would learn that they may save time by driving 65 mph instead of 75 mph because they eliminate a charging stop.

Lived experience tells me that while one may learn academically that driving a bit slower would save time overall, actually applying that knowledge is likely a bridge too far.

When we're on trips (our good hiking is 8-12 non-stop driving hours away -- Louisiana has as many mountains as it has currently allocated Slate delivery windows, as far as I can tell), there's more than a 17% difference in fuel economy based on who's driving. I have standard fuel stops for when I'm driving, as I know I can easily reach them (or beyond, if conditions are favorable). If my wife is driving, there's no way short of an epic and convenient derecho that we'll get anywhere near that far before having to refuel. (Of course, on a 12-hour drive, if she takes a good chunk of it, it won't be 12 hours long, so there is that.)

If we had to road-trip the Slate, there are likely still at least a few road segments in the mostly blank areas of the map that might require that I drive on account of charging considerations, but hey, we're not planning to do long road trips in the Slate.

The data guy in me would certainly enjoy seeing the current consumption rate, but I'd definitely want a moderately-long rolling average. My Mazda has something like that, but the time constant is so short, it's basically useless noise.

 

[E90400K]

As someone who tends to end up running late for things, I have learned that hurried driving rarely moves the arrival estimate by a meaningful amount. There's very little room for improvement, especially compared to saving time at some part of your schedule before you're on the road.

Yeah, I'd better write that down...

As one who finds the challenge in trying to beat the GPS estimated time of arrival, I find arriving ahead of time by just a minute or two quite satisfying.

 

[ElectricShitbox]

I'm aware of how the math actually plays out, but while sometimes I'm speeding because I'm late, the rest of the time I'm speeding because I like it.

 

[TPL]

90 mph is plenty for me. I grew up in the 55 era and the highways near me top out at 70. I'm happy to set the cruise at 75 and let everyone pass me.

At one point in my life I had a 90 minute commute and setting the cruise near the speed limit dramatically reduced my driving stress.

 

[E90400K]

I'm aware of how the math actually plays out, but while sometimes I'm speeding because I'm late, the rest of the time I'm speeding because I like it.

Back in Calculus 101 (when the National limit was 55 MPH) we ran the integral that shows what the top sustained speed is required (over a specified distance traveled) to hit an average speed of 55 MPH. Faded memory has left me devoid of being able to rerun the integral, but IIRC the max attained speed was somewhere north of 78 MPH.

 

[EV Trek]

Speed limit or a couple over is what I usually drive unless I feel like a rolling road block, then I may speed up some more. Also I stay out of the way of big trucks..

 

[CorvusCorvax]

As a long-time breaker of speed laws, I will say this: In my European sedans and wagons, I find that they have a particular highway speed that they "like", where chassis dynamics and wind noise and engine noise all add up and subtract to make the most comfortable driving experience. Some of those vehicles are most comfortable at 75-85mph. One of my turbo Audi sedans way back when just loved 93mph. I could get away with that speed sustained in Montana and Wyoming, but nowhere else.

Exceeding the speed limit by 10mph might not save you much time in your in-town commute. Seconds, maybe a couple of minutes at most. But on a long trip, on the interstate, +10mph over 3 hours can save you a half hour of drive time.

I rarely exceed 90mph my current cars, but I will say that both my Porsche and my BMW have seen north of 90mph in the last month. When I have my Slate (a year from now!), I'll probably not exceed 75 at any time, because its going to be a commuter, not a long-distance traveler.

 

[EV Trek]

As a long-time breaker of speed laws, I will say this: In my European sedans and wagons, I find that they have a particular highway speed that they "like", where chassis dynamics and wind noise and engine noise all add up and subtract to make the most comfortable driving experience. Some of those vehicles are most comfortable at 75-85mph. One of my turbo Audi sedans way back when just loved 93mph. I could get away with that speed sustained in Montana and Wyoming, but nowhere else.

Exceeding the speed limit by 10mph might not save you much time in your in-town commute. Seconds, maybe a couple of minutes at most. But on a long trip, on the interstate, +10mph over 3 hours can save you a half hour of drive time.

I rarely exceed 90mph my current cars, but I will say that both my Porsche and my BMW have seen north of 90mph in the last month. When I have my Slate (a year from now!), I'll probably not exceed 75 at any time, because its going to be a commuter, not a long-distance traveler.

But 10+ over in an EV will probably cost you enough range you will lose the time you thought you gained by increased charging stops and times.
Driving 75 mph cost me 50 miles of range in my Bolt than driving the speed limit of 65.

 

[Visualvalhalla]

I agree with you, CorvusCarvax. My current daily is Swedish-made, gets to 60 in just over half of Slate's time and 90mph is a jogger's pace. I've driven much faster with that car on a track.
I'll have to switch to my granny mode in my future Slate.

 

[ElectricShitbox]

But 10+ over in an EV will probably cost you enough range you will lose the time you thought you gained by increased charging stops and times.

If you're interested in the intersection between speed, efficiency, and charging rate as it pertains to driving EVs fast, check out the various Cannonball Run attempts by the Out Of Spec crew on youtube.

 

[kvermeer]

As one who finds the challenge in trying to beat the GPS estimated time of arrival, I find arriving ahead of time by just a minute or two quite satisfying.

I find trying to beat the "miles remaining" estimate much more satisfying! 60 seconds saved means I'd be keeping up with that car I can just make out car a ways up the road, not worth that much. Conversely, if the odometer estimates 150 miles left in the tank, and I get 170 through patient, attentive, skillful driving, that's meaningful cash in my pocket! Add the range estimate and the odometer and you can keep tabs on whether you're exceeding or failing the target.

When we're on trips (our good hiking is 8-12 non-stop driving hours away -- Louisiana has as many mountains as it has currently allocated Slate delivery windows, as far as I can tell), there's more than a 17% difference in fuel economy based on who's driving.

Sorry about your hikes and delivery windows. I've observed the same disparity regarding driving efficiency. When my wife drives I can see that her left foot is on either the floor or dead pedal (she only brakes with her right foot), but I swear she must be pushing down the gas and dragging the brakes at the same time to achieve the abysmal efficiency numbers she gets. She's very smart, self-controlled, and strong-willed, so it's not a limitation of ability to apply that knowledge, it's just a choice she'd have to make for herself.

 

[CorvusCorvax]

But 10+ over in an EV will probably cost you enough range you will lose the time you thought you gained by increased charging stops and times.
Driving 75 mph cost me 50 miles of range in my Bolt than driving the speed limit of 65.

You missed the part where I said that my Slate will be my commuter, and *not* my long-haul driver. Any range that I lose with driving faster will wash out in the charge cycle when I plug it in to the free charger at work.

 

[CorvusCorvax]

Conversely, if the odometer estimates 150 miles left in the tank, and I get 170 through patient, attentive, skillful driving, that's meaningful cash in my pocket!

I can always make more money. What I cannot create more of is *time*. Any time I save behind the wheel is time spent doing something more fun than playing in traffic. And even time spent with my mother-in-law is more fun than playing in traffic.

 

[EV Trek]

If you're interested in the intersection between speed, efficiency, and charging rate as it pertains to driving EVs fast, check out the various Cannonball Run attempts by the Out Of Spec crew on youtube.

A lot depends also on the charging speed of your EV, the ones they used charged much faster than both my Bolt charged (50kW max) and what the Slate (120kW max) will charge. Slower means longer time wasted recharging.