Wh/mile efficiency reported on the highway (heat on, 30°F, 85 mph)

[BayouCityBob]

I think the underlined is possibly your error

As speed increases, the drag force on the vehicle will increase more steeply for the CT than for the MY.

Their parity in range at EPA conditions is basically an artifact of the relevant battery size as relates to their respective frontal plane/Cd.

Meanwhike, there are other factors at play, such as the power-torque curve of the engine and selected gear reduction, which can affect relevant range as well. And here, the CT’s ‘sweet spot’ is possibly ‘tuned’ different/worse ar upper highway speeds than a MY, since the CT is also ‘tuned’ for low end power/torque for off-road/towing/rock crawling.

I think you will find that in your chart the percentage of additional energy required to go from say 48 mph to 70 mph is the same for the Eclipse or the Blazer. So if both start with enough energy to go the same distance at 48 mph then they will be able to go the same (shorter) distance at 70 even though the Blazer will consume far more energy in total. At least that is how I see it.

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[cvalue13]

I think you will find that in your chart the percentage of additional energy required to go from say 48 mph to 70 mph is the same for the Eclipse or the Blazer. So if both start with enough energy to go the same distance at 48 mph then they will be able to go the same (shorter) distance at 70 even though the Blazer will consume far more energy in total. At least that is how I see it.

I’ll admit I only have one eye and 2 brain cells working today. Having said that, I’m not sure I’m following.

maybe another of our fine members can arbitrate/cure me of my ignorance


While I agree that when both vehicles are at 0% they’re both at 0%, the original question I thought was “how could a CT use a greater percentage of its battery/mi when traveling at [80]mph than a MY traveling at the same speed”

the answer I’m suggesting here is that it takes more energy/mi for the CT because the drag force on the CT at [80]mph is far greater than the drag force on a MY at [80]mph (then also greater rolling resistance of the tires, and differences in efficiency due to the sweet spot of gearing of the motors].

What you show in your graph basically seems to assume both vehicles have unlimited/sufficient battery to “absorb” that extra energy.

But we’re here, I think, talking about when does that energy curve run into the “end” of the battery.

in the modified chart below, the bottom red line represents the total N of energy in the Eclipse’s tank, while the top red line represents the total N of energy in the Blazer’s tank.

the eclipse makes it the 210%, while the Blazer doesn’t

 

[Gigahorse]

yes, under EPA conditions, and straight from the horse's mouth

just based on the above alone, do the maths on a CT with a "301 mile range" at EPA conditions, and if at a sustained 75mph you're down to 210mi range

Or based on what we are seeing the EPA rating of 340 and in the real world it is down to 180, expected a drop but not that big across a 3 CT and different driver sample of over 3,000 miles.

 

[cvalue13]

Or based on what we are seeing the EPA rating of 340 and in the real world it is down to 180, expected a drop but not that big across a 3 CT and different driver sample of over 3,000 miles.

but remember, all these Foundation units come in the Goodyear ATs

So a Foundation AWD is EPA for 318

A Foundation Beast EPA rated for 301

mat least while they’re on the Goodyears (and not until someone changes shoes to the Pirelli street tires)



Take a Foundation Beast at consistent 75-80mph down a freeway, much less with some added lead-foot and/or a few PSI low, and yeah you’ll likely be seeing around 200 give or take

 

[Sjohnson20]

Driving in freezing temps kills your range. If it was 30 degrees then this sounds about right.

 

[Gigahorse]

Driving in freezing temps kills your range. If it was 30 degrees then this sounds about right.

So if it is cold, like it is in most of the country this time of year, you can expect to get 170 miles or range instead of 340?
All of the cold impacts I have seen on the X Y 3 etc have been like 25% max

 

[cvalue13]

All of the cold impacts I have seen on the X Y 3 etc have been like 25% max

collected data from over 12,000 Teslas, and 360,000 charging cycles, in temperatures less than 30 degrees Fahrenheit, the Model Y had an average range of roughly 45 percent of the EPA estimate. Model S similar.

 

[Gigahorse]

collected data from over 12,000 Teslas, and 360,000 charging cycles, in temperatures less than 30 degrees Fahrenheit, the Model Y had an average range of roughly 45 percent of the EPA estimate. Model S similar.

Less than 30 is pretty cold, though the big study that was done was based on national winter average of 30-50F?

 

[cvalue13]

Less than 30 is pretty cold, though the big study that was done was based on national winter average of 30-50F?

done on data from the vehicles - apparently they can log the car’s temp sensor and correlate to range outcomes captured in those temperatures

 

[Gigahorse]

done on data from the vehicles - apparently they can log the car’s temp sensor and correlate to range outcomes captured in those temperatures

Yea was saying that the sub 30 numbers were a LOT worse than the 30-50 numbers if I remember correctly. Something about getting below freezing 32f/0c started to make a really big difference in range.

 

[Bkb13]

collected data from over 12,000 Teslas, and 360,000 charging cycles, in temperatures less than 30 degrees Fahrenheit, the Model Y had an average range of roughly 45 percent of the EPA estimate. Model S similar.

Facts hurt!

@scottf200 provided some interesting charts that should help everyone on this thread to understand the issue.

 

[scottf200]

Facts hurt!

@scottf200 provided some interesting charts that should help everyone on this thread to understand the issue.

In my thread that provide a couple ways to look at that speed-vs-efficiency data, the MotorMatchUp site did define their inputs ... one of which was 70F. [ @cvalue13 gave me some good feedback on that thread too]

 

[Mini2nut]

The bottom line? Cybertruck owners will be Cyber disappointed with the battery range.

Keep in mind that the new 4680 batteries were all about cutting manufacturing costs, not efficiency. Tesla cut the battery cell count down to roughly 1300 cells for the Cybertruck.

 

[JBee]

I’ll admit I only have one eye and 2 brain cells working today. Having said that, I’m not sure I’m following.

maybe another of our fine members can arbitrate/cure me of my ignorance


While I agree that when both vehicles are at 0% they’re both at 0%, the original question I thought was “how could a CT use a greater percentage of its battery/mi when traveling at [80]mph than a MY traveling at the same speed”

the answer I’m suggesting here is that it takes more energy/mi for the CT because the drag force on the CT at [80]mph is far greater than the drag force on a MY at [80]mph (then also greater rolling resistance of the tires, and differences in efficiency due to the sweet spot of gearing of the motors].

What you show in your graph basically seems to assume both vehicles have unlimited/sufficient battery to “absorb” that extra energy.

But we’re here, I think, talking about when does that energy curve run into the “end” of the battery.

in the modified chart below, the bottom red line represents the total N of energy in the Eclipse’s tank, while the top red line represents the total N of energy in the Blazer’s tank.

the eclipse makes it the 210%, while the Blazer doesn’t

The aerodynamic drag for the MY and CT are substantially different, and as such energy consumption does NOT extrapolate in a linear fashion.

This means that with increasing speed a CT will experience even more range loss in comparison to a much smaller and slippery MY.

This is clearly demonstrated in the graph without the annotations, between the Hummer and Eclipse.

Simply the more sensitive a vehicle is to drag, the more the deviation with increasing airspeed.

Maybe this helps compare the MY AWD and the CT AWD, and show how a more sensitive vehicle to drag, results in more air speed induced range loss:

(NOTE: This is wh per km not wh per mile!)

Speed		Aero CT	Aero MY	CT	MY	Difference
mph	kmh			wh/km	wh/km
25	40	2.43	1.21	109	97	1.12
31	50	3.79	1.89	117	101	1.16
38	60	5.46	2.72	129	108	1.19
44	70	7.43	3.71	143	116	1.23
50	80	9.7	4.84	161	128	1.26
56	90	12.28	6.13	181	141	1.28
63	100	15.16	7.57	204	156	1.31
69	110	18.35	9.15	230	173	1.33
75	120	21.83	10.89	259	192	1.35
81	130	25.62	12.79	291	213	1.37
88	140	29.72	14.83	327	236	1.39
94	150	34.12	17.02	367	261	1.41
100	160	38.82	19.37	412	289	1.43

Note the same applies to when the drag is increased by a trailer.

So you can expect "less" range reduction with a CT than a MY whilst towing the same trailer.

PS This also means that because you have a 50% larger battery in the CT you will get better range than a MY at lower speeds where aerodynamic drag is reduced. If you want to go far, go slow with the CT!

 

[Wraven]

Facts hurt!

@scottf200 provided some interesting charts that should help everyone on this thread to understand the issue.

If I'm reading this correctly at total power? Trying to reconcile this against the EPA formula of 1 gallon of gasoline equivalent of 33.7 kilowatt hours.

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