Range predictions

[Revenant89]

Anyone predict the range being higher than Slates advertised numbers? I find it hard to believe those will be the numbers based on the EPA test cycle. The drag coefficient is predicted to be well under 0.39.

	Range (mi)	Battery Size (kWh usable)	Efficiency (mi/kWh)
Highway​	153​	50​	3.05​
City​	190​	50​	3.80​
Highway​	240​	80​	3.00​
City​	300​	80​	3.75​

 

[KevinRS]

The numbers we have seen have been preliminary estimates, just for the combined EPA, and there is no way they wanted to advertise a high range and then sell a lower range. We might hear solid numbers in June, or maybe later, may depend on actual testing with production line vehicles.

 

[GaRailroader]

I hope their estimates were conservative. I agree that the estimates seem low.

 

[Revenant89]

The numbers we have seen have been preliminary estimates, just for the combined EPA, and there is no way they wanted to advertise a high range and then sell a lower range. We might hear solid numbers in June, or maybe later, may depend on actual testing with production line vehicles.

I wish they marketed them all on the conservative side for range. KIA advertises nearly the absolute best possible range. Which you will never come close to on the highway.. and may even struggle to get with city driving.

 

[RetiredOnPaper]

Always better to under promise and over deliver. This has been the weak point of EVs; Range is advertised using new fresh batteries, trying to make the numbers look as impressive as possible.

I think Slate should drop the 2 battery option and just go with the larger battery. It would save $$$ in assembly, logistics, battery management firmware, etc. They already made a smart move by going with NACS.

 

[Kopsis]

The drag coefficient is predicted to be well under 0.39.

Predicted by who? That's pretty unrealistic for a pickup. And Slate isn't doing any aero heroics (like completely flush pop-out door handles, aero rims, heavily optimized mirrors, completely flush headlights, etc. that you see on many other EVs) so above 0.40 and probably closer to 0.43 is much more likely.

Slate's range estimates are almost certainly a little bit conservative, but they probably didn't add more than 10% margin. They don't want to catch heat from buyers if they don't meet their predictions, but scaring off potential buyers with overly conservative estimates is also bad.

 

[GaRailroader]

It looks like Tesla Cybercab is going to hit 6 miles/kWh EPA rating. Obviously that’s way more aero than Slate. Perhaps they will come out with a version with no hatch and a tailgate instead. The could call it Cyberute.

 

[beatle]

It's dumb that the range is just one number. In ICE and hybrid vehicles you have different MPG for highway and city since all vehicles have different efficiency ratings depending on the driving speed.

Further, EVs just have MPGe which is a useless metric. Who cares about comparing battery size with the energy density of gasoline? You can't fill an EV up with gas, and you can't fill up a gas car with kwh. In addition, the MPGe is made further useless by including charging losses.

 

[Revenant89]

Predicted by who?

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]

It's dumb that the range is just one number. In ICE and hybrid vehicles you have different MPG for highway and city since all vehicles have different efficiency ratings depending on the driving speed.

Further, EVs just have MPGe which is a useless metric. Who cares about comparing battery size with the energy density of gasoline? You can't fill an EV up with gas, and you can't fill up a gas car with kwh. In addition, the MPGe is made further useless by including charging losses.

Yeah it should be mi/kWh like.. 3.80 City / 3.05 Hwy / 3.43 Combined. If we're comparing efficiency.

 

[beatle]

I agree. But these numbers look low when you're used to looking at MPG. "Wow, not even 4 miles per hogshead? My Canyonero gets 12!" The EPA used the MPGe metric exclusively because it makes EVs look more favorable. Inventing this nonsense metric undermines the value of the sticker, and including mystery charging losses in this makes it even more difficult/impossible to tell if you're even getting the rated range by looking at your EV's current efficiency.

 

[Revenant89]

I don't think we can ever dumb it down enough for some people..

 

[Revenant89]

I think Slate should drop the 2 battery option and just go with the larger battery. It would save $$$ in assembly, logistics, battery management firmware, etc. They already made a smart move by going with NACS.

Totally agree.. don't see a point for the smaller battery.

 

[ElectricShitbox]

I predict 3.2mi/kwh city, 2.8mi/kwh highway. I'm basing this on 1: vibes, 2: numbers from other boxy EVs, and 3: the fact that nothing from the shape to motor/inverter is optimized for efficiency

 

[beatle]

Maybe they can start including meaningful metrics like mi/kwh or wh/mi in smaller font for those who can read.

To answer your original question, I think the ratings are somewhat reasonable. The cD may be high for an EV, but the Slate has a smaller frontal area which makes its total drag numbers more competitive. Overall efficiency could be quite high, especially in the city where drag matters less and weight matters more. Having a smaller cabin will also reduce the cold weather penalty. The Mini Cooper SE (the one vehicle I'm cross shopping with the Slate) is remarkably efficient in the city.