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Tesla Semi Acceleration Smokes The On-ramp

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I’m always dumbfounded by folks who talk about the trucks quick acceleration capabilities as if it’s something useful
Completely forgetting that most of the time there’s cargo in the trailer that you don’t want flying around everywhere
I feel you are missing the point. That means that with full load that it will do normal acceleration without the cargo (pallets) being affected (vs loaded down yaris acceleration).
 
I feel you are missing the point. That means that with full load that it will do normal acceleration without the cargo (pallets) being affected (vs loaded down yaris acceleration).
Our current fleet of Volvo’s have enough torque to accelerate reasonably without shifting the cargo or holding up traffic
Obviously much slower than cars but again you can’t just go as fast as you want you must consider the cargo


So again this whole “acceleration” thing is impressive only to people not in the trucking industry.
And unfortunately for tesla, those people aren’t buying the semi.
 
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Our current fleet of Volvo’s have enough torque to accelerate reasonably without shifting the cargo or holding up traffic
Obviously much slower than cars but again you can’t just go as fast as you want you must consider the cargo


So again this whole “acceleration” thing is impressive only to people not in the trucking industry.
And unfortunately for tesla, those people aren’t buying the semi.

Actually, faster acceleration means faster deliveries. Long ago, I followed some fleets using singles rather than duals. Because of the lower rolling resistance the run was completed fifteen minutes faster. What made this important was that they got to the destination before closing so that they could unload the same day rather than having to wait overnight to unload. Now this is just one example and obviously not applicable to all. Not having to slow down on hills is how the extra acceleration would be used. In hilly areas that could save a lot of time. Also we're not talking 0-60 in 2.5 seconds either.

My thought about why the general trucking industry isn't purchasing them now is that there aren't enough charging places and the trucks aren't actually shipping yet. Most shipping companies that I have worked with are pretty conservative (they can't afford to purchase equipment that hasn't been tested in real-life applications). It took a long time just to convince them that radial tires really did save them money--and tires are a lot less expensive than trucks. No one is expecting to change the industry overnight.
 
Actually, faster acceleration means faster deliveries. Long ago, I followed some fleets using singles rather than duals. Because of the lower rolling resistance the run was completed fifteen minutes faster. What made this important was that they got to the destination before closing so that they could unload the same day rather than having to wait overnight to unload. Now this is just one example and obviously not applicable to all. Not having to slow down on hills is how the extra acceleration would be used. In hilly areas that could save a lot of time. Also we're not talking 0-60 in 2.5 seconds either.

My thought about why the general trucking industry isn't purchasing them now is that there aren't enough charging places and the trucks aren't actually shipping yet. Most shipping companies that I have worked with are pretty conservative (they can't afford to purchase equipment that hasn't been tested in real-life applications). It took a long time just to convince them that radial tires really did save them money--and tires are a lot less expensive than trucks. No one is expecting to change the industry overnight.
I agree on the hill part, it would definitely be faster. But and I’m only speaking from my experience at our company, we make appointments for deliveries. We don’t send a truck out hoping it makes it there in time. We send it out knowing it’ll get there and will be empty at a certain time. That’s why we can have an entire day planned out for drivers

Also I’m not sure how rolling resistance affected arrival times, if the trucks are traveling at the same speed. That’s interesting


And again I’m just saying I find it funny how people are impressed with the acceleration when the fact is acceleration is not a big concern, these new trucks with automatic transmissions get up and go fairly quickly.
 
I agree on the hill part, it would definitely be faster. But and I’m only speaking from my experience at our company, we make appointments for deliveries. We don’t send a truck out hoping it makes it there in time. We send it out knowing it’ll get there and will be empty at a certain time. That’s why we can have an entire day planned out for drivers

Also I’m not sure how rolling resistance affected arrival times, if the trucks are traveling at the same speed. That’s interesting
The thing is that you can spend rolling resistance on extra speed, but of course the fuel use is the same as before.

The thing was that particular route couldn't be made from the time of departure (which was fixed) to before the destination closed. Because the truck couldn't be unloaded, it had to wait overnight until the next morning's opening to unload and return. No amount of scheduling could fix that. Sure, it's an edge case, but it was an unexpected result.
 
The thing is that you can spend rolling resistance on extra speed, but of course the fuel use is the same as before.

The thing was that particular route couldn't be made from the time of departure (which was fixed) to before the destination closed. Because the truck couldn't be unloaded, it had to wait overnight until the next morning's opening to unload and return. No amount of scheduling could fix that. Sure, it's an edge case, but it was an unexpected result.
I might not be smart enough to understand what you mean in regards to rolling resistance affecting time of arrival when both trucks drive the same speed.

Now I see what you mean about arriving late, we don’t do that type of hauling.
Our truck load and LTL business has local trucks that make pick ups within a 100 mile radius, which is then brought back to our terminal and packed into either trailers for long haul truckers or containers destined to be shipped via rail.

I tried convincing my brother (company owner) to purchase the tesla trucks to replace the local trucks since they’re only driving around a 100 mile radius.
Unfortunately those trucks run nearly non stop between 3 shifts and aren’t sitting idle long enough to charge.
As the fleet manager I’m still going to figure out a way to purchase atleast 1 or 2 of them. The amount of diesel we use really makes the gasoline savings of my tesla seem insignificant. I’d love to reduce that usage while at the same time not impacting our daily operations.
 
I might not be smart enough to understand what you mean in regards to rolling resistance affecting time of arrival when both trucks drive the same speed.
Ah. Both trucks don't drive the same speed. Given an engine that produces X amount of power, there are some drive train losses, and tire rolling resistance losses which don't change much as speed increases. There is also aerodynamic loss which increases as speed increases. If the drivetrain and/or tire losses can be reduced, there is more power available to push air, so the truck can go a bit faster.

If both trucks drove the same speed, there would be some fuel savings, but no difference in arrival time.
 
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Unfortunately those trucks run nearly non stop between 3 shifts and aren’t sitting idle long enough to charge.
This is the kind of operation I thought battery swapping would be ideal for. I have no clue if Tesla built that possibility into the semi the way they did in the S.

If we make the assumption that it takes one shift to charge the battery, you could have a maximum of 1/3 diesel and 2/3 Tesla.
1. Tesla truck goes out on first shift.
2. Diesel truck goes out on second shift.
3. Tesla truck charges on second shift
4. Tesla truck goes out on third shift
5. Diesel truck goes out on first shift
6 Tesla truck charges on first shift.
...

Well, it's a back of the napkin calculation anyway.
 
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Ah. Both trucks don't drive the same speed. Given an engine that produces X amount of power, there are some drive train losses, and tire rolling resistance losses which don't change much as speed increases. There is also aerodynamic loss which increases as speed increases. If the drivetrain and/or tire losses can be reduced, there is more power available to push air, so the truck can go a bit faster.

If both trucks drove the same speed, there would be some fuel savings, but no difference in arrival time.

Most modern over-the-road trucks only drive wide-open when climbing a grade. There is usually a significant power reserve when traveling steady-state on the highway, so reducing drivetrain losses would only improve fuel economy.

Of course, there are still some under-powered rigs out there that could benefit from any increase in power-to-the-wheels. For those vehicles, you're right.
 
Most modern over-the-road trucks only drive wide-open when climbing a grade. There is usually a significant power reserve when traveling steady-state on the highway, so reducing drivetrain losses would only improve fuel economy.
Correct, but if the route is in mountainous terrain, a few minutes could still be picked up because it doesn't matter whether you're talking aerodynamic resistance or elevation gain. Power not used to push the tires would be shifted to either. For the example I used in the original post, we're talking about 15 minutes during a day's drive with less powerful trucks (I said long ago :). As I recall, the trucks went 73 mph rather than 70 mph.
 
I tried convincing my brother (company owner) to purchase the tesla trucks to replace the local trucks since they’re only driving around a 100 mile radius.
Unfortunately those trucks run nearly non stop between 3 shifts and aren’t sitting idle long enough to charge.
As the fleet manager I’m still going to figure out a way to purchase atleast 1 or 2 of them. The amount of diesel we use really makes the gasoline savings of my tesla seem insignificant. I’d love to reduce that usage while at the same time not impacting our daily operations.
I'm curious how long it takes to load or unload a truck. Is it possible that in the future Tesla trucks will charge during that time? Obviously that means charging at the docks and an investment.
 
I'm curious how long it takes to load or unload a truck. Is it possible that in the future Tesla trucks will charge during that time? Obviously that means charging at the docks and an investment.
At our terminal the trailers are pre loaded.
Trucks arrive and simply swap trailers and head back out. It would be an inefficient use of time to have them wait for a trailer to be loaded/unloaded

At the customer it can take anywhere from 15 minutes to 6 hours.
Unfortunately I don’t ever see those places installing charging, they have literally 0 incentive to provide charging. Why would they pay for another company’s operating expenses.
 
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I'm curious how long it takes to load or unload a truck. Is it possible that in the future Tesla trucks will charge during that time? Obviously that means charging at the docks and an investment.
It just depends. If they are preloaded trailers like AMPd says, then the time is a few minutes because it's just sign, uncouple, and drive away, perhaps picking up the empty trailer that was previously unloaded. If it's palletized goods, likely 10-20 minutes, depending on how far away the fork lift has to travel to stack the pallets, and if there is more than one fork lift doing the unloading. If it's loose objects, such as tires, then it depends on how many people are unloading and palletizing. Might take as long as two hours depending upon the size of the tires. It's really a "how long is a piece of string" question. There are very few unloading situations that would be long enough for a complete charge.

I'd suggest that the Tesla semi's success in the long haul sector hinges on Tesla installed charging facilities, just as a goodly part of the S, X, 3's success hinges on Superchargers. I'd further suggest that they need to be installed in existing truck stops and rest areas because the mandated rest times are when the charging can happen, and existing truck stops have the shower, food, access, and parking facilities needed. It would be really expensive to set up an alternate network of truck stops for Teslas*. Most current SCs are designed with cars in mind (a few exceptions, such as Perry, OK which is primarily a truck stop). It shouldn't be too hard to convince truck stop property owners to allow Tesla to install truck SCs because they are always looking for an additional revenue stream, with the possible exception of those where the property is owned by the oil companies.

Something to keep in mind is that it took about 45 years between the time the first radial tires were marketed and when the became ubiquitous. Tires are replaced more often than cars or trucks.

* The only alternate network that could be practical is an electrified roadway where charging happens continually. This would only be cost effective on certain routes (at least in the near term), and would almost certainly be less expensive than building a parallel network of truck stops.
 
I’m always dumbfounded by folks who talk about the trucks quick acceleration capabilities as if it’s something useful
Completely forgetting that most of the time there’s cargo in the trailer that you don’t want flying around everywhere

As a person who has been behind a semi on an on-ramp, I say "strap down your load and buy a Tesla". Besides, the loading forces are already worse in cornering and braking, if the load is not secured, even bumps can displace it.


Merging is useful. Not backing up traffic at every red light is useful. Regeratuve braking is useful (out of scope comment). Getting away with not securing your load because your truck is slow is just lazy. Edit: May be standard practice, but seems wrong.

Edit: I see your fleet is well powered to begin with, thank you!

(Not that cargo would "fly around" anyway, it would slide on the floor)
 
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I tried convincing my brother (company owner) to purchase the tesla trucks to replace the local trucks since they’re only driving around a 100 mile radius.
Unfortunately those trucks run nearly non stop between 3 shifts and aren’t sitting idle long enough to charge.
As the fleet manager I’m still going to figure out a way to purchase atleast 1 or 2 of them. The amount of diesel we use really makes the gasoline savings of my tesla seem insignificant. I’d love to reduce that usage while at the same time not impacting our daily operations.

With the addition of one Tesla to your existing fleet, and a Mega at your terminal, you would have the time/ capacity to pull it out of rotation for the 40 minutes it would need every 2 runs (6-8 hours at 100 miles) (or 20 minutes every 3-4 hours). Sure, you would have one more truck than you do currently, but that also gives you a spare if something fails.
The extra performance might even be able to reduce the effective down time putting it on par in terms of deliveries per day.
 
Pallet to floor friction is around 0.3 Factors Affecting the Friction Coefficients between Wooden Pallets and the Wooden Floor of a Van-Type Semi Trailer

At a steady 0.3 G acceleration, 0-60 takes 9.2 seconds. Tesla semi fully loaded 0-60 is 20 seconds, tractor only is 5 seconds. So the only issue is on a lightly loaded trailer (total weight less than 40k). If the driver/ software is cautious, even unsecured pallets will stay in place.

Note: not making any claims about vertical stability.
Note: need to adjust for grade.
Note: non slip floors would help also.
 
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As a person who has been behind a semi on an on-ramp, I say "strap down your load and buy a Tesla". Besides, the loading forces are already worse in cornering and braking, if the load is not secured, even bumps can displace it.


Merging is useful. Not backing up traffic at every red light is useful. Regeratuve braking is useful (out of scope comment). Getting away with not securing your load because your truck is slow is just lazy. Edit: May be standard practice, but seems wrong.

Edit: I see your fleet is well powered to begin with, thank you!

(Not that cargo would "fly around" anyway, it would slide on the floor)
You can’t always strap every piece down, especially in a van trailer where you’re unable to get inside once it’s loaded, it’s just impossible.
Not every cargo is palletized
Slim and tall stuff would not slide around, they would tip over.

We had an incident like that where the boxes tipped over and leaned on each other. The middle stack was crushed
There was nothing our driver could do, it was the shippers fault for being too cheap to order a flat bed trailer where everything could be secured
Instead they ordered a van trailer where access to the front of middle is impossible once it’s loaded

Pallets shifting and compressing during hard acceleration is bad when hauling glass. That’s why when we load glass in a trailer we make sure to tag it on the outside to let the driver know to accelerate slowly, corner slowly and no hard braking.

Another thing to remember is we repack trailers and try and squeeze in as many packages as possible, and you can’t strap down every single box that’s stacked on each other.

I’m not saying the tesla semi is bad because it accelerates quickly, because you don’t have to floor it every single time. I was just commenting on people’s excitement over it’s acceleration capability when it’s actually not an important factor in this industry.