Apologies I was not saying you were wrong, regen in an EV is of course part of why EVs are much more efficient.
I was expanding on your point because weight has a noticeable (I mean visible) impact on efficiency overall.
Last edited:
When are you going fully electric?
- Thread starter Ricochet J
- Start date
-
- Tags
- electric
Apologies I was not saying you were wrong, regen in an EV is of course part of why EVs are much more efficient.
I was expanding on your point because weight has a noticeable (I mean visible) impact on efficiency overall.
Associate
- Joined
- 19 May 2010
- Posts
- 1,277
The regen doesn’t make any difference though. Yes you will get more electric back because you’re slowing down a larger mass, but you’ve also used more electric accelerating that mass in the first place, so they effectively cancel out (ish)
I get your argument that ICE cars don’t have any regen at all (you do have engine breaking which cuts fuel usage to zero, which isn’t the same as as adding fuel back into the tank but does help a bit) so there is a tiny advantage there, but it’s so small as to be not worth paying attention to IMO.
Imagine doing 100 miles down the motorway at a constant speed with 3 extra the car - while your braking at the end DOES add an extra AAA battery’s worth of charge back into the battery, the extra electric you’ve used to haul around that 240kg of man-meat vastly outweighs that…
Haha, 80kg per man? What is this, the cast of Time Bandits?
Sorry I’ll get my coat… try the veal.
I’m currently averaging about 3.7 miles per kWh with my iX.
Last Sunday drove a 230 mile trip to Thorpe Park - 90% M40 Motorway at 70-75mph and averaged 3.6 miles per kWh.
I’m finding aero, motor and software efficiency trumps weight & size.
This iX is more efficient than my smaller and lighter Polestar 2
The WLTP range is 264 miles - I got home with 8% battery left after 230 miles, so pretty close to achieving that with majority of the journey motorway.
Last edited:
Trying really hard to imagine 100 miles at a constant speed on the motorway in the south of England
lol, true. Though in their defence they did not specify the speed.
Had a debate on the I-Pace forum recently where I was pointing out how the I-Pace stagnation meant it was massively overtaken by other premium Crossover/SUVs. That Jaguar had ample opportunity and tech to increase efficiency by at least 25% but didn’t bother. One counter argument was that other “SUV EVs” were just as inefficient. I linked to EVDB on the iX40 to show a much heavier and larger premium SUV EV was easily 20% more efficient.
I specifically picked the iX40 because it was heavier, bigger, more premium and above all, considerably more efficient and despite having a smaller battery, gave similar range.
Still ugly compared to the I-Pace though
Last edited:
Associate
- Joined
- 19 May 2010
- Posts
- 1,277
Haha, 80kg per man? What is this, the cast of Time Bandits?
Sorry I’ll get my coat… try the veal.
As much as I (massively) sympathise with this statement, I was attempting to be generous and kind to everyone else
Weirdly, airlines use fixed weight for every passenger for the aircraft weight and balance calculations, otherwise they’d have to weigh everyone individually.
Males: 86kg in summer, 89kg in winter due to extra clothing…
They even do regular studies to see if we’re getting fatter!
EASA review of standard passenger weights in 2022 shows no significant change | EASA
The Agency conducted a survey to obtain actual data on the average mass of passengers and luggage on domestic, international, and intercontinental flights.
www.easa.europa.eu
Caporegime
Took my car to the shops and back yesterday. Started on a fresh 80% charge, ended on 81%. Er....
Associate
- Joined
- 19 May 2010
- Posts
- 1,277
Was it a battery shop…?
Beat me to it. I was going to ask if they plugged in to a charger.
ICE vehicles lose a vast amount in heat and drive train. Up to 50%.
On a motorway in an EV you'll probably do better coasting then regen. Switching to a hilly A road or if your journey is mostly downhill you'll use regen a lot more. A road is likely less open less windy and you'll be going slower so less drag.
This isn’t actually the case. Towing is impacting on range mainly because of the aero not the weight.
I could tow a 1250kg caravan or a larger 1600kg caravan and the impact on range will be within the margin of error.
It takes a tiny bit more energy to get it rolling but after that, it’s all about the aero, speed (and wind) has by far the biggest impact).
The only time you’ll see an impact is in stop start traffic through town. But you are going so slow you are not getting hammered by the aero effect which is by far the biggest sap on range so in reality it’s small. It’s also not typical to be travelling 10’s of miles in stop start traffic so even measuring it in the real world isn’t practical.
TLDR: it’s all about the aero, the weight isn’t really a material factor.
Source: I tow a caravan with an EV and did my research first. I get pretty much the same efficiency with my 1250kg caravan as the people maxing out the Model Y with larger 1600kg caravans.
Edit: **** autocorrect
Last edited:
I find on some local routes I end up using hardly any battery due to regen. Certainly extends my range on certain routes.
Indeed. But fill that same caravan with bags of cement and the efficiency will be significantly worse.
I’m not disagreeing with you, just demonstrating that it’s all about balance. At some point the scales tip from drag to weight and back again. So it’s why I said we need to keep all other factors equal.
You could not fill a caravan with bags of cement so it’s a bit of a strawman argument.
If you got a smaller, lighter trailer designed for such a load and filled it with bags of cement up to 1600kg, you’d get better efficiency than I would towing my 1250kg caravan
You could not fill a caravan with bags of cement so it’s a bit of a strawman argument.
If you got a smaller, lighter trailer designed for such a load and filled it with bags of cement up to 1600kg, you’d get better efficiency than I would towing my 1250kg caravan
Are you seriously saying it is impossible to place bags of cement into a caravan? Is there a law I have missed, either legal or scientific that states a caravan cannot hold some bags of cement?
Well a typically single axel caravan normally only has a payload of 150kg when empty regardless of size. That would take it up to it’s maximum weight per its chassis plate which it’s legal maximum weight. I think mines only 125kg.
So yes, you could put 150kg of cement in if you really want.
I’m not sure how that differs from the stuff you’d usually take when caravanning like gas bottles, food clothing, awning etc. You also have to account for any fitted accessories like a motor mover which is ~30kg, oh and a battery.
I assume he means structurally it can't hold the weight.
Its a bad example. you'd have have a van where there is no change in aerodynamics drag, or height of the vehicle then you'd see the difference.
Its all moot though as no one is driving a van and a van has the aerodynamics of a brick in the first place.
I'd guess EV drivers aren't trying to squeeze an extra 10% of range out by being lighter or driving really slowly. They'll just hit a charger for a top up, and add so much charge weight becomes irrelevant. Stopping for a few minutes on a long journey is mostly more practical.