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Old 02-26-2020, 12:46 PM   #1 (permalink)
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'Cybertrucking' the 2019 RAM(TFL cars.com)

So on the 24th,Elon Musk announced Cd 0.30 for Cybertruck,and narrowing to 82-inches.No mention about mirrors.
If you could get a long-bed,standard cab RAM,then, a Brett Herndon' Aerolid,Herndon' aerobox,plus deformable gap-seal,between cab and bed/shell would be all that was needed in order to match the drag of Cybertruck.
With a 6-1/2-foot bed,you'd need a 42-inch aerobox (boat-tail).It would actually drop you to Cd 0.299.from Cd 0.382.
With a belly pan,diffuser,passenger car mirrors,and wheel fairings you'd be looking at Cd 0.1776.And you'd be stuck there unless you went to BEV,and lost the cooling system (Cd 0.1526).23.12 mpg vs 17.0 mpg at 70-mph,on REGULAR Unleaded.30 mpg @ 70 mph with turbo-diesel (same power).
AeroStealth had a 'Cybertruck' back in 2014.He'd purchased an Aerolid and box from Brett.It dropped his F-150,from Cd 0.402,to Cd 0.305,according to CFD and wind tunnel conformation at an undisclosed wind tunnel.We ran some numbers between Monahans,Texas and Odessa,Texas,looking at 24.92 mpg,with the 3.5-l EcoBoost.Which would be around 21.66 mpg for the 5.8-L, V-8,and 28.17 mpg for a turbo-diesel,all at 100-km/h.
The rumor-mill has Cybertruck at around 68-mpg at this velocity.The motor has a really sweet BSFC-e.

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Old 02-26-2020, 01:25 PM   #2 (permalink)
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I found this conversion, which I should probably memorize. The MPGe rating seems worthless to me, and I prefer to think in terms of miles per kWh, or watts per mile.

1 MPGe = 0.029669 mi/kWh

That's 2 miles per kWh, or exactly what I predicted the Cybertruck would get (half of what cars get).

A 500 mile range CT is going to need about a 250 kWh battery. That means the 300 mile range one needs 150 kWh, and the 250 mile range needs 125 kWh.
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Old 02-26-2020, 02:16 PM   #3 (permalink)
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conversion

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Originally Posted by redpoint5 View Post
I found this conversion, which I should probably memorize. The MPGe rating seems worthless to me, and I prefer to think in terms of miles per kWh, or watts per mile.

1 MPGe = 0.029669 mi/kWh

That's 2 miles per kWh, or exactly what I predicted the Cybertruck would get (half of what cars get).

A 500 mile range CT is going to need about a 250 kWh battery. That means the 300 mile range one needs 150 kWh, and the 250 mile range needs 125 kWh.
We're closer to knowing the aerodynamics of Cybertruck.Jury's out on rolling-resistance.LT rated tires come under a different jurisdiction than P-rated tires,so they're not reported the same.And since the carmaker determines what the tire manufacturer produces for OEM,it's up to Tesla to spec the tire.We know that 'flotation' 'super-singles' on big-rigs have 20% lower R-R than 'conventional' tires.Some 'big-rig' tires have the same or better Cfr-r than some passenger car tires.The tires on Cybertruck are an unknown quantity.And it's impossible to nail down what road loads will actually be without the coefficient.Without road loads we know nothing.
I'll presume that,at the level of expertise Tesla's team operates at,they can completely model the car numerically,and predict,to a high degree of certainty,what the performance will be.I'm going to wait for 3rd-party testing before acquitting or indicting.Some Teslas are at 340-miles range right now.A 500-mile pickup seems like a walk-on home run.
'And did I tell you about the 2005 (Dodge RAM SRT) Hennesey Venom 800,$106,855,with 156-miles range and a receiver hitch?'
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Old 02-26-2020, 02:29 PM   #4 (permalink)
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I don't know what the rolling resistance of these are, but it's what I chose for my truck back in the day when I wanted a combination of light off road/snow ability (previous highway tires got stuck in 4x4 on nearly flat grass) and quiet highway performance.

They have sidewall detail that makes them look more off road capable, which might appeal to those who want that aggressive CT look.

Bridgestone Dueler AT Revo
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Old 02-26-2020, 02:48 PM   #5 (permalink)
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Originally Posted by redpoint5 View Post
I don't know what the rolling resistance of these are, but it's what I chose for my truck back in the day when I wanted a combination of light off road/snow ability (previous highway tires got stuck in 4x4 on nearly flat grass) and quiet highway performance.

They have sidewall detail that makes them look more off road capable, which might appeal to those who want that aggressive CT look.

Bridgestone Dueler AT Revo
They remind me of a Pirelli,enduro, motorcycle tire we used to run in the 1960s.It was aggressive enough for off-road traction,while still rolling smooth on pavement,and really good tread wear.Nice!
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Old 02-26-2020, 04:25 PM   #6 (permalink)
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I can wait for influx of 120v charging fails.
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Old 02-27-2020, 01:30 AM   #7 (permalink)
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Quote:
'Cybertrucking' the 2019 RAM(TFL cars.com)
...
If you could get a long-bed,standard cab RAM,then, a Brett Herndon' Aerolid,Herndon' aerobox,plus deformable gap-seal,between cab and bed/shell would be all that was needed in order to match the drag of Cybertruck.
Well, maybe but it still wouldn't be a Cybertruck.

I'm still waiting for my FUV 2+ years on. In the news, Starship SN1 is being stacked up outdoors, the assembly building is roofed and the plan is a 20km hop by Apr-Sep.

I'm looking forward to that.
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Old 02-27-2020, 08:23 AM   #8 (permalink)
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I can wait for influx of 120v charging fails.
You like seeing burned 30 year old outlets and 16 Guage extension cords?
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Old 02-27-2020, 10:19 AM   #9 (permalink)
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Question

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You like seeing burned 30 year old outlets and 16 Guage extension cords?
I would certainly hope not.
I thinking more like people trying to drive 40 or 50 miles a day on 8 to 10 hours of at home 120v charging.
You can do that with a car that gets 3 to 4 miles to a kwh.
A truck will get around 2 mIles to a kwh.
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Old 02-27-2020, 11:31 AM   #10 (permalink)
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Quote:
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I would certainly hope not.
I thinking more like people trying to drive 40 or 50 miles a day on 8 to 10 hours of at home 120v charging.
You can do that with a car that gets 3 to 4 miles to a kwh.
A truck will get around 2 mIles to a kwh.
Good point. One Bolt owner I know charges exclusively with 120v at home. 2.5 years ownership and it works for him and his wife for their daily (weekday) commuting.

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