DIY Electric Car Forums banner

1 - 20 of 127 Posts

·
Registered
Joined
·
1,466 Posts
Discussion Starter #1 (Edited)
We had a thread on this forum on over the road trucks .My point was that
Trucks get 6 to 10 mpg and gross 80,000 lbs, meaning that they get great mpg / ton. IE;a MB 320 CDI will get 32 to 40 mpg @ 5,000 lbs gross , that's 5 times less energy then the Mercedes per ton . That means battery weight will have 5 times less negative effect or like a Tesla S with a 240 lb. battery.
Elon says 20% less operating cost.
It's always been about the battery,who can make those Elon!
Oh the sports car $200,000 ,1.9 sec. 0 to 60 mph ,600 mile range with 200kwh battery.
What are the talking heads Tesla shorts going to say this morning . HE has never made a deadline, neither have 99% of people doing new hard things.
 

·
Registered
Joined
·
4,887 Posts
There certainly is a pattern in these trucks (including the Nikola Motor proposal): the cab extends forward and narrows, which is good for aerodynamics and is made easier by the lack of need for engine access or clearance for the top of an engine. Unfortunately, it makes access to the door more difficult, leading to this bizarre enter-by-the-back-door system.

I have no idea why this truck wasn't shown months - or years - ago, since there is nothing very new in it. I suppose Tesla Motors just needs some good press to offset the continuing Model 3 production disaster. :rolleyes:

How easy is it to build a prototype like this? Single-speed motor-driven axles are commercially available for large road vehicles. Multiple manufacturers offer multi-speed gearboxes specifically for electric motors (although usually in smaller sizes). Cummins currently makes only engines, and put together a battery-electric truck to promote their proposed electric powertrain products.... using a race car fabricator (which has never built a truck before) to do the work.

I think Wrightspeed has the right idea. Whether you agree with Wrightspeed's hybrid approach or prefer straight battery-electric, long-haul trucks are not a rational place to put expense and effort, if the purpose is to reduce fossil fuel consumption. Stop-and-go operation of transit (buses - already available), service (think garbage), and local delivery vehicles is a more useful but less attractive market; Cummins targeted Class 7 urban hauling with their tractor, and Mercedes Fuso chose a medium-duty straight truck.
 

·
Registered
Joined
·
4,887 Posts
"Semi"

I think it's hilarious that Musk has chosen "Semi" as the name for his truck.
Semi | Tesla

The term "semi" means "half", referring to trailers which are not full trailers (entirely supporting themselves, with wheels at both ends, like an old horse-drawn wagon) or pony trailers (balanced on one set of wheels, with only a small part of the weight carried by the tow vehicle, like recreational trailers and small trailers drawn by a single horse), but half-supported by their own wheels at the back and half-supported by the tow vehicle at the front. So it's the trailer which is a semi-trailer; the truck pulling a semi-trailer is a tractor. But sure, this might be a semi-useful truck. :D

I suppose that "Tractor" wasn't an appealing name. :rolleyes:
 

·
Registered
Joined
·
4,887 Posts
Energy consumption rate

...
Trucks get 6 to 10 mpg and gross 80,000 lbs...
Diesel contains about 10 kWh/L, or 38 kWh/USgal. 6 to 10 mpg or 0.17 to 0.10 USgal/mile is then 6.3 to 3.8 kWh/mile (of chemical energy, not electricity)... and personally I think the 6 mpg end of the range seems more likely if actually loaded anywhere near 40 tons.

With a battery-electric truck using energy output from generating stations (not the raw fuel input to them), and engine efficiency of roughly one-third, the 2 kWh/mile energy requirement claimed by Tesla seems roughly reasonable. On the other hand, Nikola Motors loudly claimed in Twitter that's low... they say "2.5 to 3.1 kWh/mi to move freight at 65-70 mph at load(Flat ground)." Of course all electric heavy truck proposals include substantial aerodynamic improvements over typical trucks - they all have sleek noses and the Tesla display model has an impossibly well-faired cab to trailer gap.

Of course, neither Tesla Motors nor Nikola Motors has an actual functioning truck, which is why they can't show them. Yes, they can drive onto a stage, but the acceleration "video" is a simplistic computer graphic, not an actual truck towing an actual loaded trailer to highway speed.
 

·
Registered
Joined
·
4,302 Posts
I think Wrightspeed has the right idea. Whether you agree with Wrightspeed's hybrid approach or prefer straight battery-electric, long-haul trucks are not a rational place to put expense and effort, if the purpose is to reduce fossil fuel consumption. Stop-and-go operation of transit (buses - already available), service (think garbage), and local delivery vehicles is a more useful but less attractive market; Cummins targeted Class 7 urban hauling with their tractor, and Mercedes Fuso chose a medium-duty straight truck.
A hybrid certainly makes more sense today. Once they improve the energy density sufficiently, or come up with a viable and standardize battery replacement system for long-haul truckers, then it will no longer make sense to have the duplicate power systems. Wrightspeed is certainly interesting, but again I would question the use of the micro-turbine - after all, I don't believe they are claiming it is actually more efficient than some piston alternatives. Something else capable of generating exactly the maximum steady-state driving power, perhaps a free piston diesel, might be more efficient.
 

·
Registered
Joined
·
1,466 Posts
Discussion Starter #10
just talked to my trucker buddy says 8mpg loaded and 120,000 miles per year 15,000 gallons per year @$3.00/gallon $45,000/ year.
1000 kWh battery X $100 /kWh =$100,000
1000kWh @$ .07/ kWh = $70.00
500 miles /8mpg= 62.5 gallons diesel X3.00/ gallon=$187.00
 

·
Registered
Joined
·
1,466 Posts
Discussion Starter #12
Thanks for posting Kevin,twice the range I didn't see that coming.
It probably cost $200,000 a year for Bugatti maintenance
 

·
Registered
Joined
·
1,466 Posts
Discussion Starter #13
The talking heads on CNN are laughing at Elon's flying car this morning , not
even mentioning the semi or hipper car. They can't be that teck illiterate.
 

·
Registered
Joined
·
4,887 Posts
These comparisons with a Bugatti Chiron are hilarious. They must start with writers who know nothing about cars, or with marketing people.

The Chiron's price has nothing to do with value or cost of construction: they exist for owners to use to flaunt their wealth. If the same car sold for twice the price, more people would want it. :rolleyes: It certainly makes it a good target for idiotic comparisons.

One comparison is the aerodynamic drag coefficient of the Telsa Semi and the Chiron. That's insane: much of that car's drag is induced due to downforce - the Chiron is not intended to be a low-drag design. Nearly every car in current production has a lower CD than a Bugatti or the Tesla Semi; they picked the Chiron because they assumed that their audience would be too ignorant to realize that it was ridiculous. An honest comparison would be with real production tractor-trailer rigs... and besides being useful it would look even better because real trucks drag coefficients run much higher than claimed for the Tesla Semi (with its unworkable trailer fairing).

In the table with the comparison with the Chiron, they should add "time to refuel" and "number of available refuelling stations". If they're going to compare performance, where are the values for lateral acceleration or lap time around a test track?

Maybe for their next model, Tesla can compare performance with a Toyota Prius, fuel economy with a Rolls-Royce, and interior room with a Ferrari. :D
 

·
Registered
Joined
·
4,887 Posts
The talking heads on CNN are laughing at Elon's flying car this morning , not even mentioning the semi or hipper car. They can't be that teck illiterate.
"teck" illiterate? :confused:

They are probably tech literate enough to know that the truck and targa coupe are not particularly interesting, that flying cars in general are a long-running joke, and that Musk's tweet about an upgrade package for the Roadster using rockets to make the car hop is a joke... so they were laughing at it.
 

·
Registered
Joined
·
1,466 Posts
Discussion Starter #16
Brian, are you saying the tesla semi and the sports car are not game changing events .If so what is interesting .
The Bugatti is not a super car and has no state of the art engineering.
It sounds like you just don't like ev's or engineering , you didn't talk about 20% less cost and the ability to do 500 miles , that's all that matters to trucking company's, except you did mention refueling but so did elon and has done it before(supercharger)
 

·
Registered
Joined
·
4,887 Posts
Brian, are you saying the tesla semi and the sports car are not game changing events .If so what is interesting .
The Semi is no more "game changing" than the other electric heavy trucks which are available, and it introduces no new technology. That doesn't mean it won't be significant when (and if) it is actually produced, but it is no miracle. PR bull doesn't do anyone any favours.

New technology is interesting. There is none in the Semi or the new Roadster.

The Bugatti is not a super car and has no state of the art engineering.
That's sarcasm, right? It's legitimately hard to tell in some of these discussions. The Bugatti Chiron is a "supercar" - a title applied to any extreme high-performance car with a huge price tag - but it's neither a heavy truck nor a competitor to the Roadster, so it's not a rational comparison point. Tesla Motors couldn't build a single car like the Chiron if Elon's life depended on it; it is certainly state-of-the-art, as are many cars.

It sounds like you just don't like ev's or engineering , you didn't talk about 20% less cost and the ability to do 500 miles , that's all that matters to trucking company's, except you did mention refueling but so did elon and has done it before(supercharger)
I find EVs interesting and I love engineering; these vehicle announcements are all about marketing and have nothing to do with engineering.

Musk's cost numbers are sheer fabrications of his imagination, and the range is both unproven and inadequate... but it isn't surprising, since anyone could predict that based on the size of the battery and a 2 kWh/mile consumption rate. Superchargers and the required (for the Semi) Megachargers are useless for the majority of long-haul trucking applications, particularly in the quantity which are likely to be available.

Yes, cost and operability are all that matter to trucking companies. The Semi is too expensive for them in general (although there will be exceptions), and operability is far from proven. Tesla Motors can't even built the Model 3 at all, or build cars of any model with 100% million-mile reliability, but they are promising million-mile truck operation. :rolleyes:
 

·
Registered
Joined
·
1,466 Posts
Discussion Starter #18
Do you think ev's , solar ,etc. are displacing hydrocarbon fuels and the reason GE's ,Peabody coal and utility's are being displaced . In fact the talking heads just yesterday said GE's stock price was due to it's dependence on utilities which have lost peak power to solar . The utilities have restricted the size of solar house installations with no pay for surplus power to home owners to limit losses.
For over 30 years the alternate energy people have warned of this displacement.
The claims made about viability which I have made are based on the simplest of engineering . drive trains over 100 years of use, weight advantage of 5 to 1 (mpg/ton) , charging ,cost and life all demonstrated with cost falling , charging infrastructure growing and cycle life growing.
Cars were hard trucks are easy.
 

·
Administrator
Joined
·
6,135 Posts
Elon didn't invent much - agree!

His EV contribution was that he understood something that has been well known for over 100 years
That Sex and Fun sell cars

The other manufacturers are still trying to sell electric cars as "Hair Shirt" specials for people who don't like cars
 
1 - 20 of 127 Posts
Top