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The Tesla Semi’s economical advantage is frighteningly underestimated

EinSV

Active Member
Feb 6, 2016
4,328
21,513
NorCal
Elon has said the Semi will have about a one-ton weight penalty versus diesel. If weight is added for a sleeper cab, it will still be a one-ton penalty -- no difference (maybe a little less since Tesla is very good at finding ways to reduce weight).

As for A/C and heat, Tesla has already developed highly efficient HVAC systems for its vehicles. In fact, Elon has mentioned many times that Tesla may even get into the home HVAC business. Other amenities for a sleeper cab shouldn't be that difficult.

Since the first couple years of the program will probably involve relatively low volumes as big companies test out prototypes before making large orders, there is probably no urgency for Tesla to roll-out a sleeper version. But I think it's a mistake to be thinking about the Semi as limited to short-haul. Tesla is definitely going after the long-haul market IMO.
 
May 13, 2019
474
1,398
Raleigh, NC
I feel the same way in that the Semi business is completely overlooked. 1st people talk about the Cars, then FSD, then Batteries. All those are huge but then you add in selling $200,000 trucks like hot cakes and FSD subscription on top of that. Money will just be flowing.
Short haul: 0-60 is going to be crazy. Charge while the trailer is being loaded/unloaded. No need to stop to fill up off the route.
Long haul: FSD is going to make fatigue way less for the drivers. The seat may as well be a LayZBoy that they can recline and take a nap.

Note: I've never driven a Semi, just a WAY outsider's POV but still think its yet another 'game changer' from Tesla.
 

TSemi

Member
Sep 7, 2020
95
107
Texas
Elon has said the Semi will have about a one-ton weight penalty versus diesel

I believe the one-ton weight penalty is all about the battery pack and nothing else.

If weight is added for a sleeper cab, it will still be a one-ton penalty -- no difference.

It will be one less ton of freight/cargo that the Tesla Semi will be able to haul legally. That one ton will also give the TS less range.

As for A/C and heat, Tesla has already developed highly efficient HVAC systems for its vehicles.

Regardless of how efficient the HVAC is it will still take more energy for more space.

Since the first couple years of the program will probably involve relatively low volumes as big companies test out prototypes before making large orders,

The first couple of years TS's will not be prototypes, that is what is being tested now. The first TS's off the production line will be the final version. That is what the companies will base their buying decisions on.

I'm confident that the Tesla Semi will be everything Elon has said it would be.
 

EinSV

Active Member
Feb 6, 2016
4,328
21,513
NorCal
I believe the one-ton weight penalty is all about the battery pack and nothing else.

It will be one less ton of freight/cargo that the Tesla Semi will be able to haul legally. That one ton will also give the TS less range.

Regardless of how efficient the HVAC is it will still take more energy for more space.

The one ton difference is the total weight difference, and the 500-600 mile range is the range fully loaded.

Far too much is made of weight. Most loads are limited by volume, not weight, and given the likely cost savings from the Semi a one-ton weight difference is not that significant even when weight is the limiting factor.

Imagine you are a transportation company CFO being presented with two choices -- the Tesla Semi or a diesel. The diesel costs 20% more per mile to operate, but 5-10% of the time it can haul 5% more. Which is the better choice?

On HVAC, both diesel and electric trucks need it. Tesla has fantastic HVAC systems on its cars -- there is no reason it wouldn't have best-in-class HVAC in the Semi.

Space would not be an issue for electric trucks any more than diesel -- if anything the opposite is true. Tesla cars have frunks because the small electric motors take up much less space and the battery is under the vehicle. The same will be done with the Semi. It also has a frunk, which is added space compared to a diesel truck, not less.

The first couple of years TS's will not be prototypes, that is what is being tested now. The first TS's off the production line will be the final version. That is what the companies will base their buying decisions on.

I'm confident that the Tesla Semi will be everything Elon has said it would be.

Thanks -- yes these are production trucks but the point is the same. Initially fleet customers are buying in relatively low volume until they can put the Semi through the paces before ordering much bigger volumes. Elon estimated that they'll sell 100,000 per year after a few years, but if they have enough battery supply I think it will eventually be much more than that since the economics will strong favor the Tesla Semi over diesel. 100,000 Tesla Semi Sales Spells $18 Billion In Revenue
 
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CyberGus

Not Just a Member
May 5, 2020
827
1,802
Austin, TX
Once zero-emission semi cabs become widely available, I can envision some municipalities regulating, restricting, or even outright banning their diesel counterparts (I'm looking at you California lol). Los Angeles is a perfect example, as they already have many regulations on atmospheric emissions due to the persistently-poor air quality. With less noise and air pollution, cities will likely start to encourage the use of ZEVs within their borders.
 
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TSemi

Member
Sep 7, 2020
95
107
Texas
Far too much is made of weight.

With BEV Semi's weight is everything. The weight of a battery pack has limits. Too much weight outweighs the benefits of having more batteries, as in range.

there is no reason it wouldn't have best-in-class HVAC in the Semi.

'Best-in-class' - sounds like an ad for Ford,GMC or Dodge trucks. LOL Do you work for an ad agency?


Space would not be an issue for electric trucks any more than diesel

With more space comes more weight. The reason for more space in a Semi is to have more room for storage such as gear, clothing, larger bedding, etc. All this means more weight which is more taxing for a BEV Semi than diesel.


but if they have enough battery supply

Giga Nevada, Giga Berlin and Giga Texas will manufacture the 4680 cells. Hopefully Giga Nevada and Texas can supply the demand for the Tesla Semi's.
 

EinSV

Active Member
Feb 6, 2016
4,328
21,513
NorCal
With BEV Semi's weight is everything. The weight of a battery pack has limits. Too much weight outweighs the benefits of having more batteries, as in range.

I've already explained why a small weight difference won't overcome the economic benefits of the Tesla Semi so we will have to agree to disagree.

I look forward to Tesla shaking up the trucking world even faster than the auto world.:)
 

scaesare

Well-Known Member
Mar 14, 2013
8,280
13,364
NoVA
Considering that Tesla’s 100 kWh batteries typically weigh around 1,300 lbs, it could then be inferred that the Semi’s battery pack would weigh around 7,800 to 13,000 lbs. This is assuming that the Semi is equipped with the same batteries that Tesla had when the Class 8 truck was unveiled. If Tesla’s 4680 cells are involved, this weight could be optimized further, considering that the company’s custom batteries are lighter and more powerful.

It's worth noting that the about 300lbs of the car pack weight is the pack casing etc... The bottom has the 1/4" thick aluminum "ballistic shielding", whereas the side and tops are relatively thin material. So I expect that majority of the weight is divided between the bottom shielding and the internal structural members.

As an individual casing would not be necessary around each of the 6-10 car-pack's worth of cells making up the Semi pack, as a percentage of overall mass the Semi pack would be smaller. It might be possible to build an entire semi pack casing for ~600-1,000lbs, rather than the 1,800-3,000 the math above would assume.
 

ThomasD

Member
Nov 22, 2019
935
403
Breckenridge Co Ky
I wonder if there will be companies turning the semi into other types of vehicles Such as tow trucks, Rescue vehicles and even a cement truck
Century-9055-on-Peterbilt-389-with-Sleeper.jpg

24e30b5ae8431a2b69f4fe1c67534dde.jpg

images
 

TSemi

Member
Sep 7, 2020
95
107
Texas
I wonder if there will be companies turning the semi into other types of vehicles Such as tow trucks, Rescue vehicles and even a cement truck
Century-9055-on-Peterbilt-389-with-Sleeper.jpg

24e30b5ae8431a2b69f4fe1c67534dde.jpg

images


That won't happen anytime soon. Any modifications to the Tesla Semi's frame will void the warranty and wreak havoc on the software that is designed only for the original frame/structure.

Maybe in the future Tesla will have something similar to Apple's Developer Program where a company can work with Tesla on getting an approved modification.
 

mongo

Well-Known Member
May 3, 2017
12,966
38,498
Michigan
Considering that Tesla’s 100 kWh batteries typically weigh around 1,300 lbs, it could then be inferred that the Semi’s battery pack would weigh around 7,800 to 13,000 lbs. This is assuming that the Semi is equipped with the same batteries that Tesla had when the Class 8 truck was unveiled. If Tesla’s 4680 cells are involved, this weight could be optimized further, considering that the company’s custom batteries are lighter and more powerful.

Traditional diesel semitrailers typically weigh around 15,000 to 25,000 lbs, which means that the Semi would likely be at a disadvantage weight-wise. To address this disadvantage, Tesla would have to ensure that the rest of the Semi is made with light and durable materials. Tesla’s extensive experience as an EV maker plays a huge part in this, as the company could use all that it has learned during the design and rollout of the Model S,3,X,Y lineup to optimize the Semi’s weight.

I'm not seeing a major weight issue. The front axle legal limit is 12,000 lbs. With the integrated motor axles, there is no frame torsion to deal with like on a diesel, so the overall structure can be lighter.

It will be one less ton of freight/cargo that the Tesla Semi will be able to haul legally. That one ton will also give the TS less range.

That is assuming the trailer grossed out before it cubed out. That is not a typical case (at least in 2008): https://info.ornl.gov/sites/publications/files/Pub37730.pdf
combinedWeights.JPG
 

TSemi

Member
Sep 7, 2020
95
107
Texas
I'm not seeing a major weight issue. The front axle legal limit is 12,000 lbs. With the integrated motor axles, there is no frame torsion to deal with like on a diesel, so the overall structure can be lighter.

The weight has to do with range. More weight = less range for a BEV.
 

mongo

Well-Known Member
May 3, 2017
12,966
38,498
Michigan
The weight has to do with range. More weight = less range for a BEV.
Sure, for a fixed pack size. In a normal situation (far from maxing out the drive train capacity), more pack can offset the additional mass, including its own mass.
Elevation changes, climate, and wind will have a larger (though variable) impact than an extra ton of weight (~2.5% change in rolling resistance if we are talking 78k lbs vs 80k).
 

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