Will the Slate’s 8 seconds to 60 mph be adequate for safe highway merging?

[Revenant89]

I tend to agree. ( I never saw better than 2.7 on the Lightning- a 7800# brick!)

Weight, frontal area, and wheel size will make a huge difference.

 

[Kopsis]

EPA range would put the EV6 RWD at around 4.2 mi/kWh. And it's nearly 1,000 pounds heavier than the Slate.

Wind RWD EPA range is 319mi with an 84 kW battery for about 3.8 mi/kWh.

 

[Doctors Do Little]

Weight, frontal area, and wheel size will make a huge difference.

My experience was that weight didn’t matter as much as wind resistance, which is why I was guessing that the aerodynamic vehicles would always do better than the truck profiles, all else equal. (Carrying a heavy load didn’t matter but pulling a tall trailer killed it.)

 

[Revenant89]

Wind RWD EPA range is 319mi with an 84 kW battery for about 3.8 mi/kWh.

Most likely 80 kWh usable though.. so 4.0 mi/kWh. I guess some of the changes dropped efficiency a hair.

 

[Revenant89]

My experience was that weight didn’t matter as much as wind resistance, which is why I was guessing that the aerodynamic vehicles would always do better than the truck profiles, all else equal. (Carrying a heavy load didn’t matter but pulling a tall trailer killed it.)

Rivian managed to get a drag coefficient of .30.. not that the Slate will be that aerodynamic. But I'm sure significantly better than the Ford.

 

[Kopsis]

Most likely 80 kWh usable though.. so 4.0 mi/kWh. I guess some of the changes dropped efficiency a hair.

Ok, but 4.0 mi/kWh that's where your 200mi estimate puts Slate efficiency with a 5% capacity derating. Do you really believe that the Slate will be as energy efficient as an EV6? Yes, there's a weight advantage, but studies have shown that with regen, weight plays a (perhaps unrealistically) low part in the EPA test loops. In the case of the EV6, the 300lb difference between the small and large battery results in a hundredths of a mi/kWh difference in the range ratings.

 

[Revenant89]

Ok, but 4.0 mi/kWh that's where your 200mi estimate puts Slate efficiency with a 5% capacity derating. Do you really believe that the Slate will be as energy efficient as an EV6? Yes, there's a weight advantage, but studies have shown that with regen, weight plays a (perhaps unrealistically) low part in the EPA test loops. In the case of the EV6, the 300lb difference between the small and large battery results in a hundredths of a mi/kWh difference in the range ratings.

If it's more akin to say the Equinox EV in drag then I suppose it would be something like 3.8 mi/KWh.

 

[Kopsis]

If it's more akin to say the Equinox EV in drag then I suppose it would be something like 3.8 mi/KWh.

Equinox EV reportedly (though unconfirmed) has a Cd of 0.34. But pickups are an aero disaster. Pickup Cd is typically 0.40 - 0.45 (though some particularly egregious examples like the lightning and Hummer EV are above 0.50. Let's give Slate the benefit of the doubt and assume 0.40 (which may be really optimistic). Frontal area difference is about 2% in favor of slate, so overall that's 15.6% more aerodynamic drag than the Equinox.

Running the efficiency numbers for Equinox, 319mi from 84 kW works out to 3.8 mi/kWh. Chevy makes a big deal about how their stated battery numbers are "usable", not "design", so no 5% derating. There's no easy way to compute the actual effect the aerodynamic difference will have on efficiency, but clearly Slate is going to be worse than 3.8 mi/kWh. I'd guess a 5 - 10% reduction, so somewhere around 3.5 mi/kWh. That still indicates that Slate's original estimates are (understandably) conservative, but not by the suggested 33%.

 

[cadblu]

If it's more akin to say the Equinox EV in drag then I suppose it would be something like 3.8 mi/KWh.

I think an Equinox EV in drag would look something like this:

 

[Driven5]

Apparently somebody did a CFD analysis on publicly available slate model, of which there are characteristic differences (like blocked of ducts) that tend result in higher Cd than real life, and got 0.39.

https://www.linkedin.com/posts/wout...aerodynamic-activity-7415067299180683264-V2W_

 

[Revenant89]

Apparently somebody did a CFD analysis on publicly available slate model, of which there are characteristic differences (like blocked of ducts) that tend result in higher Cd than real life, and got 0.39.

https://www.linkedin.com/posts/wout...aerodynamic-activity-7415067299180683264-V2W_

Nice find.. I expect it to be surprisingly efficient. Even the first gen Soul EV was 0.35.

 

[KevinRS]

There are a bunch of little things Late has done with the classic pickup form factor to improve aero. They probably ran a lot of iterations through simulations to reach what they did. Some obvious ones are look at how the door handles don't stick out, and the mini spoilers at the end of the roof and the tailgate.

 

[Doctors Do Little]

There are a bunch of little things Late has done with the classic pickup form factor to improve aero. They probably ran a lot of iterations through simulations to reach what they did. Some obvious ones are look at how the door handles don't stick out, and the mini spoilers at the end of the roof and the tailgate.

Love your optimism. In my use case, it won’t matter much, but for those who commute 75 miles each way routinely…it matters.

 

[KevinRS]

Love your optimism. In my use case, it won’t matter much, but for those who commute 75 miles each way routinely…it matters.

Not really optimism, just observation. Their running through simulations has been mentioned, and you can see the spoilers, and that the door handles, while not like Tesla, do not stick out.

 

[sodamo]

Question from the uniformed. Will wrapped vs unwrapped be a factor? What about something like some applied finish?