Orbis has a great concept. Not much out there in the way of detailed specs. At this point those powered wheels use doubled-up motors from the 'Zero' electric motorcycle. Based on that detail I speculate that the "50hp" is the peak rating that would almost certainly have a limited run time before overheating. So I'm back at the question of "continuous" horsepower.
The electric GMC fully imagined -
- Thread starter hertfordnc
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Something like this would be better suited IMO, 100hp per motor, https://chargedevs.com/newswire/two-new-in-wheel-electric-drive-systems-unveiled/
According to this article they have come very close to reducing rolling resistance, friction and air resistance to near zero:
"An all-electric Class A RV based on Tesla’s commercial semitruck is in the concept phase. The motor coach would be powered by four electric motors—like the Tesla Semi, weigh around 50,000 lbs., have a 600-mile range, and use 1.7kw of electricity per hour."
One HP = 746 watts. 1,700 w / 746 = 2.23HP!!!
Obviously someone got their decimal point in the wrong place!
www.rvtravel.com
"An all-electric Class A RV based on Tesla’s commercial semitruck is in the concept phase. The motor coach would be powered by four electric motors—like the Tesla Semi, weigh around 50,000 lbs., have a 600-mile range, and use 1.7kw of electricity per hour."
One HP = 746 watts. 1,700 w / 746 = 2.23HP!!!
Obviously someone got their decimal point in the wrong place!
Tesla electric semitruck inspires all-electric Class A RV
An all-electric Class A RV based on Tesla’s commercial semitruck is in the concept phase. The motor coach would be powered by four electric motors—like the
www.rvtravel.com
Actually it's not a decimal error but, rather, a typo. It should read that the Tesla semi will consume "1.7kw per MILE". Hence, 500 miles of range on a battery estimated at around 900kw.According to this article they have come very close to reducing rolling resistance, friction and air resistance to near zero:
"An all-electric Class A RV based on Tesla’s commercial semitruck is in the concept phase. The motor coach would be powered by four electric motors—like the Tesla Semi, weigh around 50,000 lbs., have a 600-mile range, and use 1.7kw of electricity per hour."
One HP = 746 watts. 1,700 w / 746 = 2.23HP!!!
Obviously someone got their decimal point in the wrong place!
Tesla electric semitruck inspires all-electric Class A RV
An all-electric Class A RV based on Tesla’s commercial semitruck is in the concept phase. The motor coach would be powered by four electric motors—like the
That's a funny misprint but pretty typical in stories about this new thing called electricity.
BTW, I reckon what they meant was 1.7kWh per mile.
EDIT. D'oh. Beaten to the punch.
BTW, I reckon what they meant was 1.7kWh per mile.
EDIT. D'oh. Beaten to the punch.
1.7
1.7 kW-hr per mile at $0.25/kW-hr is almost $0.50 a mile. More expensive to go down the road than our old ones with gasoline. And that's at today's prices.
(1700 W-hr/mile) * (60 miles/hr) = 102,000 watts
(102,000 watts) / (746 watts/hp) = 136 hp
Those trucks are much bigger frontal area punching through the air though, than our GMCs. So I think my back of the envelop estimate that you'd need 90 hp to push a GMC down the road makes sense.
1.7 kW-hr per mile at $0.25/kW-hr is almost $0.50 a mile. More expensive to go down the road than our old ones with gasoline. And that's at today's prices.
(1700 W-hr/mile) * (60 miles/hr) = 102,000 watts
(102,000 watts) / (746 watts/hp) = 136 hp
Those trucks are much bigger frontal area punching through the air though, than our GMCs. So I think my back of the envelop estimate that you'd need 90 hp to push a GMC down the road makes sense.
Yes. I do believe that the promise of cheap clean electricity to replace expensive dirty gasoline is is hollow one.
Not meaning to wind this into a debate, but a couple of concrete numbers for consideration. As of this moment the average price for electricity in the USA is $.16 per kw/h. So, 1.7 × .16 = $.27 per mile for the Tesla semi. Meanwhile, the national average for diesel right now is $4.89 per gallon. For a large rig managing 8 mpg that calculates to $.61 per mile for fuel. I'll let others decide if that is a significant saving or not.
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Owning 2 electric vehicles Fiat 500e and a Nissan Leaf, it’s remarkable how little hp you actually need to cruise. I can glide down the freeway in the Leaf at 55 mph and get about 4 miles to the kwh. Normal driving is more like 2.5-3 miles per kwh. A streamlined coach (no roof ac) should easily get a mile/kwh. Assuming a 300 kwh pack would give you usable range and crazy off the grid time. 75 kwh Tesla packs on ebay for ~$7.5k. That’s 30k for the battery, guesstimate 20k for drivetrain and we have ourselves quite an expensive project.
Dreiachser,
While your single point analysis may be accurate, it is obvious that you have never done vehicle road load studies. That is no surprise as these do not happen outside of vehicle testing labs that are scrambling for a fractional more MPG. The road load of any vehicle at a steady speed on level smooth pavement is usually quite low. But as soon as you include acceleration and any grade at all, it is a whole new ball game.
Matt
While your single point analysis may be accurate, it is obvious that you have never done vehicle road load studies. That is no surprise as these do not happen outside of vehicle testing labs that are scrambling for a fractional more MPG. The road load of any vehicle at a steady speed on level smooth pavement is usually quite low. But as soon as you include acceleration and any grade at all, it is a whole new ball game.
Matt
Also not wanting to get into a debate
but I used $0.25 per kw-hr b/c where I live in NY bc that's about what it costs after including the delivery fees to my house. Delivery fees to an EV charging station are higher.In NY, our single party state govt 'leaders' have decided that the Climate Action needed to save the world from the evil CO2 molecule (which is a trace level plant growth nutrient btw) is that everyone will switch over their home heating to Electricity (you know, which is primarily coal fired) _after_ shutting down NY's nuclear plants. Don't get me started on just how stupid our state government really is.
So, to summarize, I have no expectation that the cost of electricity where I live in NY will _ever_ decrease. As more and more homes transition from natural gas heat to electrical heat, the cost of electricity is only going to to up. $0.25 per kw-hr is generously low as an estimate.
But don't believe me, here's another source https://thebluedot.co/how-much-does-it-cost-to-charge-your-ev-at-public-charging-stations/ that includes the delivery fee for charging an EV. (Hint: it's not cheap!)
"The cost of charging an electric car at a public charging station depends on several factors. But to ballpark it, the average cost per kWh is between $0.40 and $0.70, and you get around 3 to 4 miles for every kWh" (this is for a car)
Using those numbers, that's $0.68-$1.19 per mile if the 1.7 kw-hour per mile number is true.
I'm hearing this also from my friends that drive EV's. The once-free charging stations are now charging both the car and their credit cards, and the cost is not _significantly_ less per mile than a small fuel efficient gasoline powered car. Surprise surprise! (sarcasm intended).
Compared to fossil fuel fired....
I'm getting 8.8mpg in my GMC, at $3.20 per gallon national average, that's $0.36 per mile.
GMC diesel conversions report 14mpg or so, at $4.89 per gallon, that's $0.35 per mile.
But I drive a diesel every day and the price difference between gas and diesel at this moment in time is unusually high. It's usually only about 20% more than gas.
I guess the takeaway is, if someone wants to go EV with their GMC it's not going to be based on a financial analysis. Not unless they do what NY is doing and takes away the fossil fuel option through legislation.
My Bolt gets 4mi/Kwh .... or .25Kwh/mi the 1.7Kwh/mi is nearly 7x the consumption .... I would expect a GMC EV to average better than 1Kwh/mi.
This is a design it, engineer it, build it, test it, and repeat scenario. It's new territory and needs to start somewhere.
Biggest challenge is moving a 12,000 vehicle up hill efficiently. Additionally, intended use is a big factor, long distant trips in a weekend, not practical, short trips with long stays may work.
This is a design it, engineer it, build it, test it, and repeat scenario. It's new territory and needs to start somewhere.
Biggest challenge is moving a 12,000 vehicle up hill efficiently. Additionally, intended use is a big factor, long distant trips in a weekend, not practical, short trips with long stays may work.
Hi all. Enjoyed the discussion above. I’ve electrified and driven (only 3 miles at 10MPH) my 1973 23’ with a 2021 Mustang Mach E electric motor and battery. Fully electric. Just drove for the first time Sunday before last. Was real smooth and had lots of power/torque.more complete discussions on Classic GMC Motorhome Facebook group, if you’re interested. John Gregory
Gregory,
Please don't restrict your discussion to Face Book. Many don't read it all because the technical side tends to be inaccurate, and I only go there as a last resort because some individuals think it is effective communication.
Matt_C
Please don't restrict your discussion to Face Book. Many don't read it all because the technical side tends to be inaccurate, and I only go there as a last resort because some individuals think it is effective communication.
Matt_C
On that note, you might also get more *consistent* and involved conversation in a forum like this vs. Facebook with people dropping in and out and maybe being more interested in expressing strong opinions vs. exploring the possibilities and talking technical aspects. A lot of the people using this forum tend to be more "do-ers" than just arm chair quarterbacks.
John,
If you have the time, we'd all like to see you start a thread in the "Build Thread" section of this forum, and share as much information about your build (past, present, future) as possible. That thread will have a lot of followers.
Hopefully we'll meet you and your electric coach at a rally one day.
Great build by the way. I saved your post of FB.
Russell
I see a "Classic GMC Motorhome Parts" facebook group but no "Classic GMC Motorhome" group. Where is it?
Facebook group posts are not well organized like a forum. You should definitely put your build on this forum in a build page
I see a "Classic GMC Motorhome Parts" facebook group but no "Classic GMC Motorhome" group. Where is it?
Facebook group posts are not well organized like a forum. You should definitely put your build on this forum in a build page
Here it is: https://www.facebook.com/groups/classicgmcmotorhomes
Classic GMC Motorhomes is Billy Massey's group and is the biggest GMC group on FB.
Good discussion about the aero and yes it is definitely CdA and not CD that is just a measure to compare shapes. Bigger frontal area is more drag. I went to the battery Show in Detroit one year and there was a company offering wheel hub motors. I don't recall the name or application, but it immediately made me think this would be ideal for the 4 rear wheels on the GMC while still keeping the flat low floor. The hub motors included regenerative braking. Hub motors are not ideal as they increase unsprung weight, but you can make the same argument about GM stating years ago they will never offer 20" wheels for the same reason. Since I am an ICE engineer I am not too fond of all electric, 4 hub motors in the rear and a diesel ICE in the front that can switch between 6 wheel drive (through the road hybrid) or act as a generator for the rear 4wheel drive. The flat gas tanks will be replaced by battery cells and a more conventinal diesel tank located behind the engine where the step is with the step pushed back, eliminating slosh issues in the flat tank
