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aerohead 02-26-2020 12:46 PM

'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.

redpoint5 02-26-2020 01:25 PM

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.

aerohead 02-26-2020 02:16 PM

conversion
 
Quote:

Originally Posted by redpoint5 (Post 617909)
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?'

redpoint5 02-26-2020 02:29 PM

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
https://www.tirerack.com/images/tire...wl_pdpfull.jpg

aerohead 02-26-2020 02:48 PM

Dueller
 
Quote:

Originally Posted by redpoint5 (Post 617915)
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
https://www.tirerack.com/images/tire...wl_pdpfull.jpg

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!

oil pan 4 02-26-2020 04:25 PM

I can wait for influx of 120v charging fails.

freebeard 02-27-2020 01:30 AM

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.

rmay635703 02-27-2020 08:23 AM

Quote:

Originally Posted by oil pan 4 (Post 617923)
I can wait for influx of 120v charging fails.

You like seeing burned 30 year old outlets and 16 Guage extension cords?

oil pan 4 02-27-2020 10:19 AM

Quote:

Originally Posted by rmay635703 (Post 617967)
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.

MetroMPG 02-27-2020 11:31 AM

Quote:

Originally Posted by oil pan 4 (Post 617976)
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.

aerohead 02-29-2020 12:39 PM

truck
 
Quote:

Originally Posted by oil pan 4 (Post 617976)
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.

The latest MOTOR TREND carried quite a bit on BEVs.Here's some numbers:
*2021 electric Ford F-150,..........................................333 Wh/mi
*2021 Cybertruck,....................................... ..............400 Wh/mi
*2020 RIVIAN,........................................... ............... 450 Wh/mi
*2020 Lordstown Endurance,....................................... 450 Wh/mi
*2021 Chevrolet/GMC HUMMER electric,......................... 500 Wh/mi
*2021 Bollinger B2,............................................... ...... 600 Wh/mi
.................................................. .................................................. ....
Some ICE,gasoline-powered pickups:
*2018 Ford F-150 Lariat,FX4 (PREMIUM fuel).................. 1400 Wh/mi (HWY)
*2019 RAM 1500 Laramie,.......................................... .. 2110 Wh/mi Ave.

redpoint5 02-29-2020 01:49 PM

I'd be impressed if the CT gets 2.5 miles per kWh in combined efficiency. I was expecting 2.

aerohead 02-29-2020 02:31 PM

2.5
 
Quote:

Originally Posted by redpoint5 (Post 618144)
I'd be impressed if the CT gets 2.5 miles per kWh in combined efficiency. I was expecting 2.

The Model X can get it's combined EPA range at a steady 70-mph.I suspect that Cybertruck will do likewise. You might see Cybertruck do 860-miles at 55-mph.The velocity-cubed power law is a real killer.

serialk11r 02-29-2020 10:42 PM

860 miles? That sounds too optimistic to me.

Offroad tires have really freaking high rolling resistance because tread hysteresis. I recall looking at some tire RR list some number of years ago. Most passenger tires were in the 0.006-0.012 range, but some offroad tire stuck out like a sore thumb at 0.017.

Just looking at the Tesla, I think the wheels are going to contribute way too much drag to hit 0.30 Cd. Maybe miracles happen though.

I think Elon's range targets might be hit with some special street-friendly tire, and the people ordering the knobbly tires are going to be pretty disappointed with the range.

ME_Andy 03-02-2020 09:15 PM

Quote:

Originally Posted by aerohead (Post 618138)
The latest MOTOR TREND carried quite a bit on BEVs.Here's some numbers:
*2021 electric Ford F-150,..........................................333 Wh/mi
*2021 Cybertruck,....................................... ..............400 Wh/mi
*2020 RIVIAN,........................................... ............... 450 Wh/mi
*2020 Lordstown Endurance,....................................... 450 Wh/mi
*2021 Chevrolet/GMC HUMMER electric,......................... 500 Wh/mi
*2021 Bollinger B2,............................................... ...... 600 Wh/mi
.................................................. .................................................. ....
Some ICE,gasoline-powered pickups:
*2018 Ford F-150 Lariat,FX4 (PREMIUM fuel).................. 1400 Wh/mi (HWY)
*2019 RAM 1500 Laramie,.......................................... .. 2110 Wh/mi Ave.

Any idea where they got those numbers? I mean, very little is known about the EV-150

JSH 03-02-2020 10:29 PM

Quote:

Originally Posted by oil pan 4 (Post 617976)
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.

I could top of my Spark EV overnight driving 50 miles per day using 110v. That was averaging 4-5 miles / kWh.

Vman455 03-02-2020 11:18 PM

Quote:

Originally Posted by ME_Andy (Post 618250)
Any idea where they got those numbers? I mean, very little is known about the EV-150

This is the only comprehensive article MT has published on upcoming electric pickups. The efficiency numbers come directly from battery capacity divided by range. However, MT estimated battery sizes (conjecture for every truck in the article except Rivian and Bollinger; no one else has announced battery capacities) and range (again, conjecture for every truck in the article; none of the trucks have received an EPA rating as yet, although Tesla does state "250 mi/300 mi/500mi (EPA est.)" on its website for the three versions of the Cybertruck), so these numbers could be way off--we don't have any way to know yet. As you point out, we know next to nothing about the EV F-150, and even Tesla has said nothing about the pack sizes that will be offered in the Cybertruck (in fact, Tesla hasn't even stated the actual capacities of the various Model 3 batteries--so I wouldn't expect to see that number published for the Cybertruck anytime soon).

aerohead 03-04-2020 11:10 AM

860-miles
 
Quote:

Originally Posted by serialk11r (Post 618173)
860 miles? That sounds too optimistic to me.

Offroad tires have really freaking high rolling resistance because tread hysteresis. I recall looking at some tire RR list some number of years ago. Most passenger tires were in the 0.006-0.012 range, but some offroad tire stuck out like a sore thumb at 0.017.

Just looking at the Tesla, I think the wheels are going to contribute way too much drag to hit 0.30 Cd. Maybe miracles happen though.

I think Elon's range targets might be hit with some special street-friendly tire, and the people ordering the knobbly tires are going to be pretty disappointed with the range.

*I just used the performance of the Model X as a shoot-from-the-hip guide.At 55-mph,the long range version has a 426-mile range.70-mph knocks that down to 325-miles.Again,you really pay for speed.
*As to the tires,they remain an unknown quantity.However,as I've said elsewhere,Tesla has control over tire design.We know from Class-8,88,000-lb ,18-wheel semis,that their 10-wheel companions,with flotation tires have 20% less rolling resistance.Those big fatties may actually have lower R-R than what you think.And their size could play into a virtual area-rule,sectional density function,enhancing the pressure profile down the entire length of the truck,mitigating spanwise-flow,boundary layer contamination-induced longitudinal vorticity.Cybertruck has two other features which play into this same issue.
I've slept with Hucho since last Saturday.I can't imagine Cybertruck's naked body coming in,any higher than Cd 0.28.Cd 0.30 with honkin' truck mirrors.
*Cybertruck is a fastback.Fastbacks have the lowest drag of all body forms.Cybertruck is a 'Kammback.' 'Kammbacks' have the lowest drag of all fastbacks.Cybertrucks proportions are identical to Volkswagen's XL1,Cd 0.189.
Cybertruck's front champfer,body side camber,tumblehome,and raked greenhouse (an industry 1st) probably compensate for the hard leading edges.Cybertruck's boat-tailing is an industry 1st.Cybertrucks stagnation point is an industry 1st.Cybertruck's bonnet,frunk profile is an industry 1st.Cybertruck's windscreen saturation is an industry 1st.Cybertruck has an industry 1st belly.Cybertruck's backlight slope,at 10-degrees to horizontal,is incapable of producing edge vorticity.Cybertruck's roof camber is an advantage.
*Aerodynamically,Cybertruck is an F-117 Nighthawk.It uses every trick used by Lockheed.
*Dassault System's, Exa Corporation POWERFLOW CFD is a full-Navier-Stokes Equation program.It's results rival any world class wind tunnel.I suspect that Elon Musk and crew already know the numbers.It's unimaginable that they wouldn't.If Tesla's hit their 'combined' range at a constant 70-mph,and Cybertruck is rated 500-miles combined,It ought to return 500-miles at 70 mph,and 860-miles at 55-mph.You can test the velocity difference relationship with your own vehicle.

aerohead 03-04-2020 11:28 AM

where
 
Quote:

Originally Posted by ME_Andy (Post 618250)
Any idea where they got those numbers? I mean, very little is known about the EV-150

All came from the manufacturers,best I can tell.
Ford has constructed an ( at least did the R&D) EV,beginning around 1909. In the 1990s,they constructed a BEV Ranger pickup to meet California's zero-emissions mandate.BEV isn't anything new to them.GM had their electric S-10 and EV1.Chrysler had their electric T-van.
What's new is,radical competition in the pickup market,which is an extremely lucrative,competitive,however,not necessarily technology-driven market segment.Elon Musk has changed all that.Aerodynamics has been stifled for almost a hundred years now (98-years).Cybertruck represents the 1922 Jaray technology hated by all stylists.It threatens the very existence of these 'Paris dressmakers',as Alfred P. Sloan Jr. referred to them.And unfortunately,unless the legacy carmakers mimic Cybertruck in 'appearance',they have no way to compete with it's performance.It's shape is it's range.

Tahoe_Hybrid 03-31-2020 11:49 AM

Quote:

Originally Posted by serialk11r (Post 618173)
860 miles? That sounds too optimistic to me.

Offroad tires have really freaking high rolling resistance because tread hysteresis. I recall looking at some tire RR list some number of years ago. Most passenger tires were in the 0.006-0.012 range, but some offroad tire stuck out like a sore thumb at 0.017.

Just looking at the Tesla, I think the wheels are going to contribute way too much drag to hit 0.30 Cd. Maybe miracles happen though.

I think Elon's range targets might be hit with some special street-friendly tire, and the people ordering the knobbly tires are going to be pretty disappointed with the range.

I got rid of the Bridgestone dullers (on the drive wheels) it did improve my MPG by a lot..

swapped them out with Michelin energy saver about 10 pounds lighter in weight.. gave me a big boost in MPG.. from 25-27 on the highway to 27 to 31.5 on the highway


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